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Where to buy machine screw assortment?
I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so either I'm Superman or the machine screws I buy from Lowe's are made out of junk steel. I guess the upside is that at least the screwheads don't strip first :o/ Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. Thanks. |
Where to buy machine screw assortment?
John Doe wrote:
I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so either I'm Superman or the machine screws I buy from Lowe's are made out of junk steel. I guess the upside is that at least the screwheads don't strip first :o/ Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. I assume that you're tapping the holes first, right? If not, that's your problem. Screws should thread into tapped holes very easily. If your tap is extremely worn, that might be the problem. Or you could be using the wrong size of tap. Or you might not be cleaning out the swarf from the hole after tapping. But I doubt you could break even the cheapest screws by simply threading them into correctly tapped and cleaned holes. Best wishes, Chris |
Where to buy machine screw assortment?
Christopher Tidy wrote:
John Doe wrote: I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so [apparently] the machine screws I buy from Lowe's are made out of junk steel. Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. I assume that you're tapping the holes first, right? If not, that's your problem. Screws should thread into tapped holes very easily. If your tap is extremely worn, that might be the problem. Or you could be using the wrong size of tap. Or you might not be cleaning out the swarf from the hole after tapping. But I doubt you could break even the cheapest screws by simply threading them into correctly tapped and cleaned holes. I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. Best wishes, Chris |
Where to buy machine screw assortment?
John Doe wrote:
snip I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. You shouldn't be breaking even the poorest screws just threading them into a tapped hole without tightening them. Something is seriously wrong here. Either that or you're trolling :-). Try McMaster-Carr. They may have sets of screws. Best wishes, Chris |
Where to buy machine screw assortment?
Christopher Tidy wrote:
John Doe wrote: snip I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. You shouldn't be breaking even the poorest screws just threading them into a tapped hole without tightening them. Something is seriously wrong here. Either that or you're trolling :-). Like by ignoring the question and for some strange reason insisting that threading a machine screw into a properly tapped hole is the only valid application for a machine screw. Plastic screws into properly tapped holes. Threading screws into a hole is not the end objective. The objective is to keep the pieces together. I can tell that the bolts aren't strong enough, that's why I ask for better. Try McMaster-Carr. They may have sets of screws. If they are better than the apparent crap I get at Lowe's. Best wishes, Chris Path: newsdbm02.news.prodigy.net!newsdst02.news.prodigy. net!prodigy.com!newscon02.news.prodigy.net!prodigy .net!border1.nntp.dca.giganews.com!nntp.giganews.c om!local02.nntp.dca.giganews.com!nntp.bt.com!news. bt.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 25 Feb 2008 16:37:38 -0600 Message-ID: Date: Mon, 25 Feb 2008 22:33:12 +0000 From: Christopher Tidy User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.0.1) Gecko/20020921 Netscape/7.0 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Lines: 19 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 86.140.192.94 X-AuthenticatedUsername: NoAuthUser X-Trace: sv3-N9CNBS1VVIyyhJNfvt5eNwoG2AejMCF25RgGWhpVLBVNG/sz4vALdIkHlvC5ZK2+e9nYIPliKOb2wUL!Mbn+n4fE0Ta3HtgG jqmPR7GkRgVlr1MKMptUoo75Mt6BOYSMzOtzYQNrXHpSrHfw X-Complaints-To: X-DMCA-Complaints-To: X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.37 Bytes: 1866 Xref: prodigy.net rec.crafts.metalworking:952333 X-Received-Date: Mon, 25 Feb 2008 17:37:40 EST (newsdbm02.news.prodigy.net) |
Where to buy machine screw assortment?
|
Where to buy machine screw assortment?
John Doe wrote:
Christopher Tidy wrote: John Doe wrote: I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so [apparently] the machine screws I buy from Lowe's are made out of junk steel. Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. I assume that you're tapping the holes first, right? If not, that's your problem. Screws should thread into tapped holes very easily. If your tap is extremely worn, that might be the problem. Or you could be using the wrong size of tap. Or you might not be cleaning out the swarf from the hole after tapping. But I doubt you could break even the cheapest screws by simply threading them into correctly tapped and cleaned holes. I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. I agree with Christopher here in that something is very wrong with what you are doing or the you are seriously failing to provide the whole picture. I would suggest though that you may want to look at thread forming fasteners which are often used for ductile materials such as Aluminium, drill the hole fit the fastener, but you need to work out it is suitable for your job which sounds like a problem at the moment .. Best wishes, Chris |
Where to buy machine screw assortment?
John Doe wrote:
Christopher Tidy wrote: John Doe wrote: snip I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. You shouldn't be breaking even the poorest screws just threading them into a tapped hole without tightening them. Something is seriously wrong here. Either that or you're trolling :-). Like by ignoring the question and for some strange reason insisting that threading a machine screw into a properly tapped hole is the only valid application for a machine screw. Plastic screws into properly tapped holes. Threading screws into a hole is not the end objective. The objective is to keep the pieces together. I can tell that the bolts aren't strong enough, that's why I ask for better. Try McMaster-Carr. They may have sets of screws. If they are better than the apparent crap I get at Lowe's. Best wishes, Chris Path: newsdbm02.news.prodigy.net!newsdst02.news.prodigy. net!prodigy.com!newscon02.news.prodigy.net!prodigy .net!border1.nntp.dca.giganews.com!nntp.giganews.c om!local02.nntp.dca.giganews.com!nntp.bt.com!news. bt.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 25 Feb 2008 16:37:38 -0600 Message-ID: Date: Mon, 25 Feb 2008 22:33:12 +0000 From: Christopher Tidy User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.0.1) Gecko/20020921 Netscape/7.0 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Lines: 19 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 86.140.192.94 X-AuthenticatedUsername: NoAuthUser X-Trace: sv3-N9CNBS1VVIyyhJNfvt5eNwoG2AejMCF25RgGWhpVLBVNG/sz4vALdIkHlvC5ZK2+e9nYIPliKOb2wUL!Mbn+n4fE0Ta3HtgG jqmPR7GkRgVlr1MKMptUoo75Mt6BOYSMzOtzYQNrXHpSrHfw X-Complaints-To: X-DMCA-Complaints-To: X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.37 Bytes: 1866 Xref: prodigy.net rec.crafts.metalworking:952333 X-Received-Date: Mon, 25 Feb 2008 17:37:40 EST (newsdbm02.news.prodigy.net) I suspect that you don't even know what you don't know. Drill and tap the "bottom" part correctly for a machine screw of your choice. Drill a hole in the "top" part slightly larger than the body of said screw. Place the screw through the top part and turn it into the threaded hole of the bottom part. The top part will now be held tight to the bottom part by the head of the screw. Randy |
Where to buy machine screw assortment?
Randy Replogle spamgoeshere1 verizon.net wrote:
I suspect that you don't even know what you don't know. Heya Bert. Drill and tap the "bottom" part correctly for a machine screw of your choice. Drill a hole in the "top" part slightly larger than the body of said screw. Place the screw through the top part and turn it into the threaded hole of the bottom part. The top part will now be held tight to the bottom part by the head of the screw. I know that. Unfortunately it has nothing to do with the question or my current situation. Maybe I should have just asked for better machine screws without any description, but some people prefer to know what's going on. Randy Path: newssvr25.news.prodigy.net!newsdbm05.news.prodigy. net!newsdst01.news.prodigy.net!prodigy.com!newscon 04.news.prodigy.net!prodigy.net!newsfeed.telusplan et.net!newsfeed2.telusplanet.net!newsfeed.telus.ne t!cycny01.gnilink.net!spamkiller.gnilink.net!gnili nk.net!trnddc08.POSTED!dac53cad!not-for-mail From: Randy Replogle spamgoeshere1 verizon.net User-Agent: Thunderbird 2.0.0.9 (Windows/20071031) MIME-Version: 1.0 Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? References: RiGwj.9530$5K1.1780 newssvr12.news.prodigy.net 47C33540.90704 cantabgold.net T3Hwj.2792$fX7.296 nlpi061.nbdc.sbc.com 47C34228.4020708 cantabgold.net 51Iwj.14060$R84.12941 newssvr25.news.prodigy.net In-Reply-To: 51Iwj.14060$R84.12941 newssvr25.news.prodigy.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Lines: 84 Message-ID: emIwj.4576$R_5.2863 trnddc08 Date: Mon, 25 Feb 2008 23:40:58 GMT NNTP-Posting-Host: 71.98.111.128 X-Complaints-To: abuse verizon.net X-Trace: trnddc08 1203982858 71.98.111.128 (Mon, 25 Feb 2008 18:40:58 EST) NNTP-Posting-Date: Mon, 25 Feb 2008 18:40:58 EST Xref: prodigy.net rec.crafts.metalworking:952347 |
Where to buy machine screw assortment?
John Doe wrote:
Randy Replogle spamgoeshere1 verizon.net wrote: I suspect that you don't even know what you don't know. Heya Bert. Drill and tap the "bottom" part correctly for a machine screw of your choice. Drill a hole in the "top" part slightly larger than the body of said screw. Place the screw through the top part and turn it into the threaded hole of the bottom part. The top part will now be held tight to the bottom part by the head of the screw. I know that. Unfortunately it has nothing to do with the question or my current situation. Maybe I should have just asked for better machine screws without any description, but some people prefer to know what's going on. Bingo. This is a discussion forum, not just a free information service. Most of the members are very knowledgeable and appreciate polite give-and-take discussion. |
Where to buy machine screw assortment?
On Mon, 25 Feb 2008 21:20:49 GMT, John Doe
wrote: I guess the upside is that at least the screwheads don't strip first When I bought my lifetime guaranteed screw drivers from Lee Valley, I asked if the guarantee still applied, even if the Phillips drivers were only used for removal and never for installation. Gerry :-)} London, Canada |
Where to buy machine screw assortment?
David Billington djb djbillington.freeserve.co.uk wrote:
John Doe wrote: Christopher Tidy cdt22NOSPAM cantabgold.net wrote: John Doe wrote: I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so [apparently] the machine screws I buy from Lowe's are made out of junk steel. Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. I assume that you're tapping the holes first, right? If not, that's your problem. Screws should thread into tapped holes very easily. If your tap is extremely worn, that might be the problem. Or you could be using the wrong size of tap. Or you might not be cleaning out the swarf from the hole after tapping. But I doubt you could break even the cheapest screws by simply threading them into correctly tapped and cleaned holes. I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. I agree with Christopher here in that something is very wrong with what you are doing Is there something wrong with asking for better machine screws in the UK? or the you are seriously failing to provide the whole picture. Considering how badly the picture is being distorted, more is clearly not better for a troll. I need better/stronger machine screws. I'm seriously not understanding why anyone would suggest that machine screw quality makes no difference, and that all that matters is threading the screw into a correctly tapped hole. How to use machine screws sounds like a completely different subject. I would suggest though that you may want to look at thread forming fasteners which are often used for ductile materials such as Aluminium, drill the hole fit the fastener, but you need to work out it is suitable for your job which sounds like a problem at the moment . And that is something stronger. Besides a stronger machine screw (at least stronger than junk steel), maybe something different will work too. I might go with stainless steel. The fitting must be extremely tight. A correctly tapped hole will not work. I will look into thread forming fasteners, but I've heard that a machine screw into aluminum can do that. Unfortunately, as I keep trying to get the message across, the cheap machine screws I have give way under too little pressure. I know they aren't going to be strong enough for my application. Path: newssvr25.news.prodigy.net!newsdbm05.news.prodigy. net!newsdbm04.news.prodigy.net!newsdst01.news.prod igy.net!prodigy.com!newscon04.news.prodigy.net!pro digy.net!goblin1!goblin.stu.neva.ru!news2.euro.net !zen.net.uk!demorgan.zen.co.uk!reader02.news.zen.c o.uk.POSTED!not-for-mail Date: Mon, 25 Feb 2008 23:35:12 +0000 From: David Billington djb djbillington.freeserve.co.uk User-Agent: Thunderbird 2.0.0.4 (X11/20070604) MIME-Version: 1.0 Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? References: RiGwj.9530$5K1.1780 newssvr12.news.prodigy.net 47C33540.90704 cantabgold.net T3Hwj.2792$fX7.296 nlpi061.nbdc.sbc.com In-Reply-To: T3Hwj.2792$fX7.296 nlpi061.nbdc.sbc.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Lines: 64 Message-ID: 47c350b0$0$2452$fa0fcedb news.zen.co.uk Organization: Zen Internet NNTP-Posting-Host: 87dfa0e2.news.zen.co.uk X-Trace: DXC=Jg8dJ?[HoU:NUZ?eo:NnN9YjZGX^207P;`MJMoM3PF=O3MZ\hk1UW9Mm :1SW=fF2OBkAGBo9B fb[477J_\X2 X-Complaints-To: abuse zen.co.uk Xref: prodigy.net rec.crafts.metalworking:952345 |
Where to buy machine screw assortment?
I would try to buy bolts that are properly graded for anything
important (above golding a picture frame on the wall). i |
Where to buy machine screw assortment?
John Doe wrote:
Christopher Tidy wrote: John Doe wrote: snip I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. You shouldn't be breaking even the poorest screws just threading them into a tapped hole without tightening them. Something is seriously wrong here. Either that or you're trolling :-). Like by ignoring the question and for some strange reason insisting that threading a machine screw into a properly tapped hole is the only valid application for a machine screw. Plastic screws into properly tapped holes. Threading screws into a hole is not the end objective. I didn't say it was. You've misread what I wrote. Best wishes, Chris |
Where to buy machine screw assortment?
Randy Replogle wrote:
snip I suspect that you don't even know what you don't know. Drill and tap the "bottom" part correctly for a machine screw of your choice. Drill a hole in the "top" part slightly larger than the body of said screw. Place the screw through the top part and turn it into the threaded hole of the bottom part. The top part will now be held tight to the bottom part by the head of the screw. That's another possibility, that he might be tapping the holes in both parts. If so the starts and ends of the threads may not be aligned, so that the two parts act like a locknut. If this is the problem, only tap the hole in the part furthest from the head of the screw. Drill a clearance hole in the other part. Best wishes, Chris |
Where to buy machine screw assortment?
John Doe wrote:
snip Maybe I should have just asked for better machine screws without any description, but some people prefer to know what's going on. Okay. It would really help if you could post a picture of the two parts and the failed screw. Then it would be much less a case of guesswork. If you don't have any web space, e-mail the picture to me and I'll host it for you: cdt22 AT cantabgold. DOT net Best wishes, Chris |
Where to buy machine screw assortment?
Jim Stewart jstewart jkmicro.com wrote:
John Doe wrote: Randy Replogle spamgoeshere1 verizon.net wrote: I suspect that you don't even know what you don't know. Heya Bert. Drill and tap the "bottom" part correctly for a machine screw of your choice. Drill a hole in the "top" part slightly larger than the body of said screw. Place the screw through the top part and turn it into the threaded hole of the bottom part. The top part will now be held tight to the bottom part by the head of the screw. I know that. Unfortunately it has nothing to do with the question or my current situation. Maybe I should have just asked for better machine screws without any description, but some people prefer to know what's going on. Bingo. This is a discussion forum, not just a free information service. So you want a little discussion before answering my question? I usually prefer a concise question, from someone asking for help. Most of the members are very knowledgeable and appreciate polite give-and-take discussion. Yeah, I'm ****ed at crap machine screws from Lowe's messing up my project, and I guess it shows. It's definitely not a beautiful day in the neighborhood here. Whether it's understood or not, once again. I'm simply asking about where to buy stronger machine screws than the zinc plated type I get at Lowe's. And maybe whether stainless steel is the only way to significantly increase strength from those type of machine screws that break when you torque them. Are those machine screws acceptable for anything? I'm surprised anyone in this metalworking group would appear to be defending them. Path: newsdbm02.news.prodigy.net!newsdst02.news.prodigy. net!prodigy.com!newscon02.news.prodigy.net!prodigy .net!border1.nntp.dca.giganews.com!nntp.giganews.c om!local02.nntp.dca.giganews.com!nntp.omsoft.com!n ews.omsoft.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 25 Feb 2008 18:10:38 -0600 Date: Mon, 25 Feb 2008 16:10:41 -0800 From: Jim Stewart jstewart jkmicro.com User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.2) Gecko/20070222 SeaMonkey/1.1.1 MIME-Version: 1.0 Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? References: RiGwj.9530$5K1.1780 newssvr12.news.prodigy.net 47C33540.90704 cantabgold.net T3Hwj.2792$fX7.296 nlpi061.nbdc.sbc.com 47C34228.4020708 cantabgold.net 51Iwj.14060$R84.12941 newssvr25.news.prodigy.net emIwj.4576$R_5.2863 trnddc08 xwIwj.14063$R84.7196 newssvr25.news.prodigy.net In-Reply-To: xwIwj.14063$R84.7196 newssvr25.news.prodigy.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Message-ID: PoOdncUBK_FjxV7anZ2dnUVZ_hzinZ2d omsoft.com Lines: 24 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 168.150.237.230 X-Trace: sv3-doI9GYJrVrKdkbjBozVUBdXMEUhFJWA7HOkLdr+MO0KPyurGIU XodCgG6JLV/PVDXtPs5t0LzJ39QTW!j7c89v1vdNZfaYUTRcTe5i7ehzr3dbO db4md63TCII/IV8yMCvryAt68/bXUpofCM7G+M/D9CoNJ!LW2ehsHZfbTy X-Complaints-To: abuse omsoft.com X-DMCA-Complaints-To: abuse omsoft.com X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.37 Bytes: 2456 Xref: prodigy.net rec.crafts.metalworking:952352 X-Received-Date: Mon, 25 Feb 2008 19:10:43 EST (newsdbm02.news.prodigy.net) |
Where to buy machine screw assortment?
Christopher Tidy cdt22NOSPAM cantabgold.net wrote:
John Doe wrote: snip Maybe I should have just asked for better machine screws without any description, but some people prefer to know what's going on. Okay. It would really help if you could post a picture of the two parts and the failed screw. Then it would be much less a case of guesswork. Your "guesswork" would go out of orbit. If you don't have any web space, e-mail the picture to me and I'll host it for you: cdt22 AT cantabgold. DOT net Best wishes, Chris Path: newsdbm02.news.prodigy.net!newsdst02.news.prodigy. net!prodigy.com!newscon02.news.prodigy.net!prodigy .net!border1.nntp.dca.giganews.com!nntp.giganews.c om!local02.nntp.dca.giganews.com!nntp.bt.com!news. bt.com.POSTED!not-for-mail NNTP-Posting-Date: Mon, 25 Feb 2008 18:38:58 -0600 Message-ID: 47C35E99.5070101 cantabgold.net Date: Tue, 26 Feb 2008 00:34:33 +0000 From: Christopher Tidy cdt22NOSPAM cantabgold.net User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.0.1) Gecko/20020921 Netscape/7.0 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? References: RiGwj.9530$5K1.1780 newssvr12.news.prodigy.net 47C33540.90704 cantabgold.net T3Hwj.2792$fX7.296 nlpi061.nbdc.sbc.com 47C34228.4020708 cantabgold.net 51Iwj.14060$R84.12941 newssvr25.news.prodigy.net emIwj.4576$R_5.2863 trnddc08 xwIwj.14063$R84.7196 newssvr25.news.prodigy.net Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Lines: 17 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 86.139.203.140 X-AuthenticatedUsername: NoAuthUser X-Trace: sv3-5Jwqk//bFaK8PH1kquAOow0F2WaObI9QL0kQC+MAJWZLTCoN1/Nv6R4JJ+t9BekNUf3SU8bGeCv+4HQ!BdWDR1gy5bZMFnVQoJ18 +raL4RgnnAUxRhxFSwQk5f6nh/9xekZWXNRiQDvs3EiSfQ== X-Complaints-To: abuse btinternet.com X-DMCA-Complaints-To: abuse btinternet.com X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.37 Bytes: 1957 Xref: prodigy.net rec.crafts.metalworking:952359 X-Received-Date: Mon, 25 Feb 2008 19:39:02 EST (newsdbm02.news.prodigy.net) |
Where to buy machine screw assortment?
On Tue, 26 Feb 2008 00:21:54 GMT, John Doe
wrote: If you want strong, buy HoloKrome screws. I believe J&L is in the UK. Pete Keillor |
Where to buy machine screw assortment?
John Doe wrote:
David Billington djb djbillington.freeserve.co.uk wrote: John Doe wrote: Christopher Tidy cdt22NOSPAM cantabgold.net wrote: John Doe wrote: I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so [apparently] the machine screws I buy from Lowe's are made out of junk steel. Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. I assume that you're tapping the holes first, right? If not, that's your problem. Screws should thread into tapped holes very easily. If your tap is extremely worn, that might be the problem. Or you could be using the wrong size of tap. Or you might not be cleaning out the swarf from the hole after tapping. But I doubt you could break even the cheapest screws by simply threading them into correctly tapped and cleaned holes. I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. I agree with Christopher here in that something is very wrong with what you are doing Is there something wrong with asking for better machine screws in the UK? or the you are seriously failing to provide the whole picture. Considering how badly the picture is being distorted, more is clearly not better for a troll. I need better/stronger machine screws. I'm seriously not understanding why anyone would suggest that machine screw quality makes no difference, and that all that matters is threading the screw into a correctly tapped hole. How to use machine screws sounds like a completely different subject. I would suggest though that you may want to look at thread forming fasteners which are often used for ductile materials such as Aluminium, drill the hole fit the fastener, but you need to work out it is suitable for your job which sounds like a problem at the moment . And that is something stronger. Besides a stronger machine screw (at least stronger than junk steel), maybe something different will work too. I might go with stainless steel. The fitting must be extremely tight. A correctly tapped hole will not work. I will look into thread forming fasteners, but I've heard that a machine screw into aluminum can do that. Unfortunately, as I keep trying to get the message across, the cheap machine screws I have give way under too little pressure. I know they aren't going to be strong enough for my application. OK, _I'll_ give it a try. I'll give you some facts and some comments: Fact: Taking perfectly good machine screws and forcing them into untapped, undersized holes in aluminum will break them, regardless of grade or quality. Comment: So, logically, if a machine screw breaks when you force it into an untapped, undersized hole in aluminum, it doesn't mean that it's a bad screw, it means that you aren't applying it correctly. Fact: Jamming a fastener into a hole where it doesn't belong doesn't make a 'nice tight joint'. It makes a poorly made, undependable joint. It's kind of like tying a quadruple granny knot: it's hard to take apart when you want it apart, but when you _don't_ want it apart it'll fail. Comment: So, logically, you shouldn't do that. Fact: The strength of a bolted joint doesn't correlate well with the fastener torque unless you're using clean, properly dimensioned threads. Comment: Uh -- you can figure this one out. Fact: Loctite is your friend. Comment: So, logically, if you want a properly made, permanently fastened screw joint, you should get decent screws and put them in with Loctite red or something stronger. If Loctite red isn't strong enough for you, see if there's anyone on this group that you haven't alienated and ask (nicely) for advise on the right stuff to use. I have never had problems with the fasteners that I get from Home Depot. I treat them like grade 2 bolts, and everyone is happy. If I need something stronger I get it from McMaster or Small Parts, and everyone is happy. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" gives you just what it says. See details at http://www.wescottdesign.com/actfes/actfes.html |
Where to buy machine screw assortment?
On Tue, 26 Feb 2008 00:44:51 GMT, John Doe
wrote: Hey JD, Don't buy ANYTHING that has a "slot-head". Put a decent chamfer on the clearance bolt-holes. Some screws, in fact most screws, have a root radius, which is why you place a washer under the head. Try a proper supplier, like Fastenal or somebody's "Nut & Bolt" Company locally, or any mill supply house. Ask for "Grade 8" in whatever style you need. Be prepared to spend more money than at Lowes, but depending on what and where and how many you buy, the best Holo-chrome's might not be a lot more bucks. Personally, I find that Allen-head bolts are less likely to break than cap screws. Not sure you can buy "machine screws" in Grade 8, but purchased from a good supplier they will be at least Grade 5. Twice (at least) in previous replies you mentioned using stainless bolts rather than the zinc-plated machine screws used at present. You should note they S/S are NOT stronger that good steel bolts. In fact, may be quite a bit softer if they are not also Grade 8 or better. "Stainless" is a quality of the material, and not directly related to strength or holding/breaking capacity. Take care. Good luck. Brian Lawson, Bothwell, Ontario. |
Where to buy machine screw assortment?
On Feb 25, 1:20 pm, John Doe wrote:
I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so either I'm Superman or the machine screws I buy from Lowe's are made out of junk steel. I guess the upside is that at least the screwheads don't strip first :o/ Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. Thanks. I have done many time what you are describing, only using self- drilling sheet metal screws and an electric drill to drive them. You and I were both over torquing the screws. Somewhere there is a table of allowable torque on the screw you are using. If you can find a toque indicating screwdriver and limit your indicated torque to the amount allowed for that screw, you will be home free. The Lowe's screws are undoubtably made in China qand are usually junk. Try a company like Fastenall for good screws. Good luck, Paul |
Where to buy machine screw assortment?
The Lowe's screws are undoubtably made in China qand are usually junk. Try a company like Fastenall for good screws. Even buying from Fastenal is no guarantee of quality. Lots of their stuff is from interesting sources. I especially see it in small (#6) setscrews. They spin the socket out very easily. For that application I buy HoloChrome from MSC. #6, #8 and #10? Fastenal stuff is OK. If you are trying to screw them into an unthreaded hole in aluminum, it isn't going to matter if they are hand made by elves from unobtainium barstock and lubed with yak butter---the little buggers are going to break. |
Where to buy machine screw assortment?
On 2008-02-25, John Doe wrote:
I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so either I'm Superman or the machine screws I buy from Lowe's are made out of junk steel. The latter is more likely. But -- by "halfway through" to you mean with the screw half-way into the aluminum? You are asking about machine screws, not self-taping screw, based on the subject line of your posting, so I have to ask: "Are you tapping the holes prior to trying to install the screws?" Machine screws are *not* designed to make their on threads. If by "halfway through" you mean "when you have about half of the screws the project requires installed and tightened" then there is something else seriously wrong, and junk metal is quite likely. I guess the upside is that at least the screwheads don't strip first :o/ :-) Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. What I would suggest is black oxide finished screws, unless you need to have light colored screws. Go to someplace like MSC: http://www.mscdirect.com and register there (you have to register before making your first purchase) and then they will send you a massive catalog ("the Big Book") which you can use to look up tools and supplies more easily than I find their web based presence to allow. Then you can phone in a purchase (remembering the account number you got when you registered) and typically they will deliver by the next day. (Hopefully you are not in Canada, because they insist on using UPS for delivery, and UPS insists on charging a customs brokerage fee on packages to Canada.) Note that you will find the prices for a box of 100 screws better than the prices for 10 screws of the same size in Home Depot. I don't have a convenient Lowes to compare to for prices, but I would expect them to be similar to Home Depot. Good Luck, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Where to buy machine screw assortment?
Brian Lawson wrote:
On Tue, 26 Feb 2008 00:44:51 GMT, John Doe wrote: Hey JD, Don't buy ANYTHING that has a "slot-head". Put a decent chamfer on the clearance bolt-holes. Some screws, in fact most screws, have a root radius, which is why you place a washer under the head. Try a proper supplier, like Fastenal or somebody's "Nut & Bolt" Company locally, or any mill supply house. Ask for "Grade 8" in whatever style you need. Be prepared to spend more money than at Lowes, but depending on what and where and how many you buy, the best Holo-chrome's might not be a lot more bucks. Personally, I find that Allen-head bolts are less likely to break than cap screws. Not sure you can buy "machine screws" in Grade 8, but purchased from a good supplier they will be at least Grade 5. Twice (at least) in previous replies you mentioned using stainless bolts rather than the zinc-plated machine screws used at present. You should note they S/S are NOT stronger that good steel bolts. In fact, may be quite a bit softer if they are not also Grade 8 or better. "Stainless" is a quality of the material, and not directly related to strength or holding/breaking capacity. Right, strength. It doesn't have to be noncorrosive, so yeah I was asking about stainless steel's relative strength. Thanks. Take care. Good luck. Brian Lawson, Bothwell, Ontario. |
Where to buy machine screw assortment?
On 2008-02-26, John Doe wrote:
David Billington djb djbillington.freeserve.co.uk wrote: John Doe wrote: Christopher Tidy cdt22NOSPAM cantabgold.net wrote: John Doe wrote: I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so [apparently] the machine screws I buy from Lowe's are made out of junk steel. [ ... ] I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. I agree with Christopher here in that something is very wrong with what you are doing Is there something wrong with asking for better machine screws in the UK? or the you are seriously failing to provide the whole picture. Considering how badly the picture is being distorted, more is clearly not better for a troll. I need better/stronger machine screws. I'm seriously not understanding why anyone would suggest that machine screw quality makes no difference, and that all that matters is threading the screw into a correctly tapped hole. How to use machine screws sounds like a completely different subject. This sentence from your initial post: "Halfway through, the machine screw twists apart just below the head." leaves us uncertain whether you are saying that each screw breaks before the head bottoms (in which case there is some problem other than simple quality of the fastener) or that you start getting broken screws before you have half of the screws installed and tightened. We are trying to figure out exactly what the conditions are under which the screws are breaking, and a lot of the initial answers were addressing the implied condition that the screws were breaking before they were fully into the workpiece -- that is, before the head was even clamping down the other part. We make suggestions, and you attack. ISTR that you came in with a similar behavior a couple of months ago or so. We're *trying* to help, and to do that, we need to understand the precise conditions under which the screws are breaking. You seem to have later suggested that the holes are properly drilled and tapped, but it is not totally clear that was what you said. I took two interpretations and answered both of them with my initial response before reading more than your original post. I would suggest though that you may want to look at thread forming fasteners which are often used for ductile materials such as Aluminium, drill the hole fit the fastener, but you need to work out it is suitable for your job which sounds like a problem at the moment . And that is something stronger. Besides a stronger machine screw (at least stronger than junk steel), maybe something different will work too. I might go with stainless steel. The fitting must be extremely tight. A correctly tapped hole will not work. Huh? A correctly tapped hole is the starting point for using a machine screw -- either in the workpiece, or in a matching nut. BTW -- it does *not* take Superman to wring off 6-32 screws. They are the weakest for their size of any common screw. The threads are too deep relative to the size. I will look into thread forming fasteners, but I've heard that a machine screw into aluminum can do that. A machine screw should *not* be asked to do that into aluminum, or any other material. There are screws specifically made for the task, but the standard zinc-plated screws are not. So -- does this mean that you are not drilling and tapping the holes? Just drilling them? Do you assume that the term "tapping" means to mark the location with a center punch? I've seen people make that assumption. Unfortunately, as I keep trying to get the message across, the cheap machine screws I have give way under too little pressure. Little pressure -- or before you even get the screw in far enough for the head to contact? This is the kind of detail which can make a difference in you getting useful answers. Of course you can get better screws. I posted MSC as a possible source. Others have pointed to a couple of other sources. I even suggested the black oxide finished screws instead of the zinc plated ones. They tend to be much harder screws. I know they aren't going to be strong enough for my application. None are if you are trying to form the threads with the screws, unless you purchase specific thread forming screws. Now to read the rest of this, and *try* to resist commenting again. Good Luck, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
Where to buy machine screw assortment?
On Mon, 25 Feb 2008 23:18:25 GMT, John Doe
wrote: Christopher Tidy wrote: John Doe wrote: snip I need more strength than just enough to thread the machine screw through a correctly tapped and cleaned hole. If the screw is going to break so easily, it probably won't hold the pieces together either. That's my problem. You shouldn't be breaking even the poorest screws just threading them into a tapped hole without tightening them. Something is seriously wrong here. Either that or you're trolling :-). Like by ignoring the question and for some strange reason insisting that threading a machine screw into a properly tapped hole is the only valid application for a machine screw. Plastic screws into properly tapped holes. Threading screws into a hole is not the end objective. The objective is to keep the pieces together. I can tell that the bolts aren't strong enough, that's why I ask for better. Any steel screw will have greater strength than the aluminum they are threaded into. If you are twisting the head off I'd agree with previous posters that there's a problem with the threads in the aluminum or that you are over toqueing the screw. |
Where to buy machine screw assortment?
Jim Levie wrote:
Any steel screw will have greater strength than the aluminum they are threaded into. If you are twisting the head off I'd agree with previous posters that there's a problem with the threads in the aluminum or that you are over toqueing the screw. Would you agree that a harder/stronger higher grade bolt takes more torque to break? |
Where to buy machine screw assortment?
"DoN. Nichols" dnichols d-and-d.com wrote:
We are trying to figure out exactly what the conditions are under which the screws are breaking, And I'm trying to tell "we" that it really doesn't matter. and a lot of the initial answers were addressing the implied condition that the screws were breaking before they were fully into the workpiece Better to go with the stated condition, that the screws were breaking with too little torque. Since you don't know how much torque I apply, you'll just have to take my word for it. We make suggestions, and you attack. ISTR that you came in with a similar behavior a couple of months ago or so. And you're planning to tell your imaginary kill file friend on me. We're *trying* to help, and to do that, we need to understand the precise conditions under which the screws are breaking. You seem to have later suggested that the holes are properly drilled and tapped, but it is not totally clear that was what you said. I've said this several times already. I'm asking about bolt strength, not about methods. Talking about methods is misconstruing my original post. I mentioned the method because it happened to be how I determined that the bolts on using are crap. Doesn't matter if I am holding the small end of the bolt in a vice, the bolt breaks too easily. How else am I supposed to determine bolt strength? Why isn't that method okay? What other method would you suggest for me to get an idea of bolt strength? Screw it into a correctly tapped hole? Little pressure -- or before you even get the screw in far enough for the head to contact? This is the kind of detail which can make a difference in you getting useful answers. I've gotten plenty of useful answers about screw strength, IMO, probably at least enough already. Some people aren't inclined to give useful answers. Some people just don't know (for example, folks living in the UK when asked about "USA chain stores"). Some people just want to talk about fastening stuff, and that's okay with me. Now to read the rest of this, and *try* to resist commenting again. Good luck. Good Luck, DoN. -- Email: dnichols d-and-d.com | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- Path: newsdbm02.news.prodigy.net!newsdst02.news.prodigy. net!prodigy.com!newscon02.news.prodigy.net!prodigy .net!news-out.readnews.com!transit4.readnews.com!postnews.go ogle.com!news3.google.com!out04a.usenetserver.com! news.usenetserver.com!in02.usenetserver.com!news.u senetserver.com!in03.usenetserver.com!news.usenets erver.com!spln!extra.newsguy.com!newsp.newsguy.com !news2 From: "DoN. Nichols" dnichols d-and-d.com Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? Date: 26 Feb 2008 05:39:31 GMT Organization: D and D Data Lines: 131 Message-ID: slrnfs79gi.k0j.dnichols Katana.d-and-d.com References: RiGwj.9530$5K1.1780 newssvr12.news.prodigy.net 47C33540.90704 cantabgold.net T3Hwj.2792$fX7.296 nlpi061.nbdc.sbc.com 47c350b0$0$2452$fa0fcedb news.zen.co.uk CYIwj.7001$Mw.6323 nlpi068.nbdc.sbc.com NNTP-Posting-Host: p14d1bfbfff000000ade30a24b698db619ab11862bc6ed4f5. newsdawg.com User-Agent: slrn/0.9.8.1pl1 (SunOS) Xref: prodigy.net rec.crafts.metalworking:952417 X-Received-Date: Tue, 26 Feb 2008 00:39:45 EST (newsdbm02.news.prodigy.net) |
Where to buy machine screw assortment?
Trying to thread a machine screw into some aluminum.
You could be getting galling on the threads, where the aluminum gets "gummy" under pressure and stops being a good sliding surface for the steel. You might try lubricating the threads before assembly, using antiseize, or even going to a thread insert (like Helicoil or Keensert) in the aluminum. --Glenn Lyford |
Where to buy machine screw assortment?
On Tue, 26 Feb 2008 05:32:50 GMT, with neither quill nor qualm, John
Doe quickly quoth: Brian Lawson wrote: On Tue, 26 Feb 2008 00:44:51 GMT, John Doe wrote: Hey JD, Don't buy ANYTHING that has a "slot-head". Put a decent chamfer on the clearance bolt-holes. Some screws, in fact most screws, have a root radius, which is why you place a washer under the head. Try a proper supplier, like Fastenal or somebody's "Nut & Bolt" Company locally, or any mill supply house. Ask for "Grade 8" in whatever style you need. Be prepared to spend more money than at Lowes, but depending on what and where and how many you buy, the best Holo-chrome's might not be a lot more bucks. Personally, I find that Allen-head bolts are less likely to break than cap screws. Not sure you can buy "machine screws" in Grade 8, but purchased from a good supplier they will be at least Grade 5. I was taught to use Grade 5 or better bolts in the automotive world. Good stuff. Twice (at least) in previous replies you mentioned using stainless bolts rather than the zinc-plated machine screws used at present. You should note they S/S are NOT stronger that good steel bolts. In fact, may be quite a bit softer if they are not also Grade 8 or better. "Stainless" is a quality of the material, and not directly related to strength or holding/breaking capacity. Right, strength. It doesn't have to be noncorrosive, so yeah I was asking about stainless steel's relative strength. Thanks. Since I'm using more and more ACQ treated lumber, the need for non-corroding hardware has led me to stainless research. McMaster has half a dozen stainless alloys and their differences astounded me. From their comparison chart + delving into the individuals: 17-4 PH Stainless Steel, 140,000 psi Combines the high-strength of alloy with corrosion resistance of stainless steel. 18-8 Stainless Steel, 70,000 psi Offers excellent corrosion resistance; it may be mildly magnetic. Alloy 20 Stainless Steel, 80,000 psi Also known as Carpenter 20, it's nonmagnetic and especially resistant to stress corrosion. 300 Stainless Steel, 80,000 psi Meet more stringent specifications such as military specifications. All are passivated (a nitric acid treatment that creates a passive film to protect the stainless steel from oxidation and corrosion). 316 Stainless Steel, 80,000 psi Offers even better corrosion than 18-8 stainless steel. It contains molybdenum, which increases resistance to chlorides and sulfates. It may be mildly magnetic. 450 Stainless Steel, 170,000 psi Offers more corrosion resistance than alloy steel. Unrated hardware, Class 2A, has a 60,000 psi strength. Grade 5 with a zinc plating is double the strength at 120,000 psi. -- Such is the irresistible nature of truth that all it asks, and all it wants, is the liberty of appearing. -- Thomas Paine |
Where to buy machine screw assortment?
"John Doe" wrote in message ... A correctly tapped hole will not work. I will look into thread forming fasteners, but I've heard that a machine screw into aluminum can do that. Unfortunately, as I keep trying to get the message across, the cheap machine screws I have give way under too little pressure. I know they aren't going to be strong enough for my application. The answer to your question is no. Screws are not made to work in incorrectly tapped holes so you can get them very tight. Weld the pieces together. Use locktite, go troll the cat news groups. -- Roger Shoaf About the time I had mastered getting the toothpaste back in the tube, then they come up with this striped stuff. |
Where to buy machine screw assortment?
On Tue, 26 Feb 2008 06:02:23 GMT, John Doe
wrote: Jim Levie wrote: Any steel screw will have greater strength than the aluminum they are threaded into. If you are twisting the head off I'd agree with previous posters that there's a problem with the threads in the aluminum or that you are over toqueing the screw. Would you agree that a harder/stronger higher grade bolt takes more torque to break? Absolutely the higher grade screws will be stronger than the ungraded "mystery metal" screws at the local hardware store - but on small #6 and #8 screws you can easily surpass the breaking strength of even the highest grades with a hand screwdriver and a "Don't know my own strength!" wrist. Been there, Done that, Have the T-Shirt. Too much torque is still too much torque. If you get too good of screws that will take being over-torqued without failure, you'll just start pulling the threads out of the aluminum fitment they are screwed into. They do make torque screwdrivers that click when you reach the proper setting. If you can't feel when it's tight, you might want to invest in one. And there are design limits for screws - if the assembly isn't strong enough a "super screw" isn't going to buy you much. You need to increase the screw size, use multiple screws, or redesign so that a bracket or tab takes the load, and it's not all on a screw in tension. -- Bruce -- |
Where to buy machine screw assortment?
John Doe wrote:
I'm doing an important project. Trying to thread a machine screw into some aluminum. Halfway through, the machine screw twists apart just below the head. The heads breaking off is not uncommon here. I don't put all that much pressure on them, so either I'm Superman or the machine screws I buy from Lowe's are made out of junk steel. I guess the upside is that at least the screwheads don't strip first :o/ Is stainless steel necessary, or is there an assortment of zinc plated (or whatever similar type) machine screws/nuts made out of decent steel someplace on the Internet or at a USA chainstore? I need sizes like 6, 8, & 10. I don't know if you can find any commodity-grade stuff that is much better. You can get certified aircraft-grade fasteners from an approved source, but they will cost a lot more. Still have to watch out for counterfeit stuff there, too. I buy stuff like this in 100-piece boxes. For electronic-style stuff (ie binding head phillips machine screws), I buy it from Digi-Key. Lately I have had to go to stainless for ROHS reasons, the zinc-plated stuff is non-compliant for some reason. For other stuff like socket head cap screws and button head (Allen) screws I get them from MSC. I have had some with no threads, way off-size allen sockets, etc. But, I have had no problem with screws breaking off - from either source. 6-32 is the weakest standard screw thread, due to the ratio of minor diameter to major dia., so if that is the size you are using, it's an added complication. You might also want to check the quality of your taps, the way you use the taps, the size of the pilot hole, etc. The screws should go in effortlessly. If there is significant binding, then the thread is off in some manner, or the hole isn't clean. I use spiral-flute taps (not spiral POINT) as much as possible, they can be run in in one continuous motion, producing a chip similar to a long, curly drill chip. This makes it much easier to clean the hole after tapping. I rip a little piece of a paper towel off and twist it into a thin cone and poke it into the hole and twirl it to get the chips out. (Professional shops use compressed air, but my family would object to this late at night.) Jon |
Where to buy machine screw assortment?
John Doe wrote:
Like by ignoring the question and for some strange reason insisting that threading a machine screw into a properly tapped hole is the only valid application for a machine screw. Plastic screws into properly tapped holes. Threading screws into a hole is not the end objective. The objective is to keep the pieces together. I can tell that the bolts aren't strong enough, that's why I ask for better. The point here is that if the screw is binding in the thread, and requires more than a twist of the finger to put it in with NO load, it will bind a LOT WORSE under axial load. This is probably the MOST common failure mode of a screw or bolt. The thread binds up to the point that the shank fails in torsion, not from axial tension. Without knowing more about what size bolt/screw, what kind of tension you are trying to achieve, what alloy and how much thread engagement there is, it is REAL hard to advise further. If you need 1000 Lbs of axial force out of a 6-32 screw, you need to go up a couple sizes. If a 1/2-13 is breaking off at only 1000 Lbs axial load, you have to be doing something wrong, or the bolts are made out of recycled beer cans. Jon |
Where to buy machine screw assortment?
"Roger Shoaf" shoaf nospamsyix.com wrote:
"John Doe" jdoe usenetlove.invalid wrote in message news:CYIwj.7001$Mw.6323 nlpi068.nbdc.sbc.com... A correctly tapped hole will not work. I will look into thread forming fasteners, but I've heard that a machine screw into aluminum can do that. Unfortunately, as I keep trying to get the message across, the cheap machine screws I have give way under too little pressure. I know they aren't going to be strong enough for my application. The answer to your question is no. I'm satisfied with the other answers. Screws are not made to work in incorrectly tapped holes so you can get them very tight. That's not really what I wanted to know. Weld the pieces together. Can't do that. Use locktite, Maybe. go troll the cat news groups. Go **** yourself. -- Roger Shoaf About the time I had mastered getting the toothpaste back in the tube, then they come up with this striped stuff. Path: newsdbm02.news.prodigy.net!newsdst02.news.prodigy. net!prodigy.com!newscon02.news.prodigy.net!prodigy .net!border1.nntp.dca.giganews.com!nntp.giganews.c om!postnews.google.com!news3.google.com!sn-xt-sjc-05!sn-xt-sjc-10!sn-xt-sjc-01!sn-post-sjc-01!supernews.com!corp.supernews.com!not-for-mail From: "Roger Shoaf" shoaf nospamsyix.com Newsgroups: rec.crafts.metalworking Subject: Where to buy machine screw assortment? Date: Tue, 26 Feb 2008 07:37:48 -0800 Organization: member of SYIX.COM Message-ID: 1204040205.495979 news01.syix.com Reply-To: "Roger Shoaf" shoaf nospamsyix.com References: RiGwj.9530$5K1.1780 newssvr12.news.prodigy.net 47C33540.90704 cantabgold.net T3Hwj.2792$fX7.296 nlpi061.nbdc.sbc.com 47c350b0$0$2452$fa0fcedb news.zen.co.uk CYIwj.7001$Mw.6323 nlpi068.nbdc.sbc.com X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 Cache-Post-Path: news01.syix.com!unknown 66-53-122-149.stkn.mdsg-pacwest.com X-Cache: nntpcache 3.0.2 (see http://www.nntpcache.com/) X-Complaints-To: abuse supernews.com Lines: 26 Bytes: 1932 Xref: prodigy.net rec.crafts.metalworking:952479 X-Received-Date: Tue, 26 Feb 2008 10:37:03 EST (newsdbm02.news.prodigy.net) |
Where to buy machine screw assortment?
" wrote:
Trying to thread a machine screw into some aluminum. You could be getting galling on the threads, where the aluminum gets "gummy" under pressure and stops being a good sliding surface for the steel. Yeah, I think so, and apparently others have hinted at that when talking about lubricant. Thanks. You might try lubricating the threads before assembly, using antiseize, or even going to a thread insert (like Helicoil or Keensert) in the aluminum. --Glenn Lyford Much to my pleasant surprise, the primary fastener looks like it might do the job without any extra strength, so the hole can be wide enough for just pushing a strong bolt through and securing it on the other side with a nut. And that will hopefully function as a momentary/temporary hold in case things start to fall apart. |
Where to buy machine screw assortment?
John Doe wrote:
snip? And that is something stronger. Besides a stronger machine screw (at least stronger than junk steel), maybe something different will work too. I might go with stainless steel. The fitting must be extremely tight. A correctly tapped hole will not work. I will look into thread forming fasteners, but I've heard that a machine screw into aluminum can do that. So you are attempting to drive a machine screw into an untapped hole? Please don't see this question as being confrontational; I'm just trying to figure out exactly what's going on. There could be a number of reasons why you need a close fitting thread. If it's for location, try to rethink the design. Use dowel pins or a milled slot for location, and screws in clearance holes to hold the joint together. But if you must have precise, close fitting threads you can buy special taps for the purpose. Screw threads are assigned various classes of fit, which range from a close fit to a loose fit. You will need to buy special taps for a close fit. They're used in instrument manufacture. They'll cost more, but they are available. If you want a close fit to prevent the screws from coming undone due to vibration, use spring washers or loctite instead. Either way, driving machine screws into unthreaded holes will break them. Even if they're really good screws. Best wishes, Chris |
Where to buy machine screw assortment?
Christopher Tidy wrote:
So you are attempting to drive a machine screw into an untapped hole? I was asking for specific locations to buy stronger/better screws, but the information about grades and stuff is probably at least as useful. Best wishes, Chris |
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