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What's just slightly smaller OD than 1/8" NPT thread????
Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded
end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/17/2013 5:25 PM, Jim Wilkins wrote:
wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... -- |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... 9mm 1.25 is a fairly common metric thread. |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad ... You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... What's the chance that it is 3/8-16 or 3/8-24? I was in line at the bearing supply store behind an alternate-energy inventor who was picking up the 2.000" ID pillow blocks he had special-ordered for a 2" pipe mast. Before he drove his electric car all the way home I had a polite little chat with him about the actual size and loose tolerance of water pipe, and where along his way he might find a 2.000" scrap hydraulic cylinder rod. jsw |
What's just slightly smaller OD than 1/8" NPT thread????
dpb wrote:
On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... -- Briggs engine would be metric. The only item on them that I know of that is a more common thread would be the oil pressure switch which is 1/4" NPT. -- Steve W. |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/17/2013 6:31 PM, Jim Wilkins wrote:
wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad ... You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... What's the chance that it is 3/8-16 or 3/8-24? .... Zero. Thread pitch is more like 27-28 -- my eyes/bifocals aren't good enough over the length of the section to tell it from a 1/8" NPT as said which is 27. Problem is, a new 1/8 nipple doesn't fit either so it's not that the die I'm using is off... -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/17/2013 6:27 PM, PrecisionmachinisT wrote:
wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... 9mm 1.25 is a fairly common metric thread. But 9 mm is only .315 whereas the tubing is just under .375 OD so a 9 mm would rattle around inside. Smaller, but too much smaller. Actually, 9.5 might be close--is there such a thing as 9.5 mm 1.10? I couldn't even find a 9 mm tap/die in town at the usual haunts--8 and 10, no 9. -- |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message ... Thread pitch is more like 27-28 -- my eyes/bifocals aren't good enough over the length of the section to tell it from a 1/8" NPT as said which is 27. Problem is, a new 1/8 nipple doesn't fit either so it's not that the die I'm using is off... -- The thread pitch on lamp fittings is 27tpi. http://sizes.com/materls/lampFit.htm Art |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message ... On 6/17/2013 6:27 PM, PrecisionmachinisT wrote: wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... 9mm 1.25 is a fairly common metric thread. But 9 mm is only .315 No that is 8mm. 9 mm = 354 whereas the tubing is just under .375 OD so a 9 mm would rattle around inside. Smaller, but too much smaller. Actually, 9.5 might be close--is there such a thing as 9.5 mm 1.10? I couldn't even find a 9 mm tap/die in town at the usual haunts--8 and 10, no 9. -- |
What's just slightly smaller OD than 1/8" NPT thread????
On Mon, 17 Jun 2013 17:56:14 -0500, dpb wrote:
On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... See http://mdmetric.com/tech/tict.htm for all you ever needed to know about threads |
What's just slightly smaller OD than 1/8" NPT thread????
On Mon, 17 Jun 2013 20:26:28 -0500, dpb wrote:
On 6/17/2013 6:27 PM, PrecisionmachinisT wrote: wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... 9mm 1.25 is a fairly common metric thread. But 9 mm is only .315 whereas the tubing is just under .375 OD so a 9 mm would rattle around inside. Smaller, but too much smaller. Actually, 9.5 might be close--is there such a thing as 9.5 mm 1.10? I couldn't even find a 9 mm tap/die in town at the usual haunts--8 and 10, no 9. 9mm xtra fine was used for flywheel to crankshaft on Subaru EA81 (and EA82 and several other Subaru engines. Don't know about curret production |
What's just slightly smaller OD than 1/8" NPT thread????
DPB:
I ran the NPT all the way thru Ya THINK that might mess up the taper? nahhh... it's just there for pretty, right? I, personally, don't own any tapered pipe taps that can be run all the way through the stock. All mine have bigger shanks than the largest part of the taper. If the male workpiece doesn't go ALL the way through to the other side of the die, and the tap ALL the way to its shoulders in the female part, they usually won't fit... They don't call it a "tapered thread" for nothing. Lloyd |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message
... On 6/17/2013 6:31 PM, Jim Wilkins wrote: wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad ... You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... What's the chance that it is 3/8-16 or 3/8-24? ... Zero. Thread pitch is more like 27-28 -- my eyes/bifocals aren't good enough over the length of the section to tell it from a 1/8" NPT as said which is 27. Problem is, a new 1/8 nipple doesn't fit either so it's not that the die I'm using is off... -- 3/8-27 (1/8IPS) is the standard thread for lamp fittings. http://www.grandbrass.com/help.cfm jsw |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/18/2013 5:41 AM, Lloyd E. Sponenburgh wrote:
DPB: I ran the NPT all the way thru Ya THINK that might mess up the taper? nahhh... it's just there for pretty, right? I, personally, don't own any tapered pipe taps that can be run all the way through the stock.... Not talking about a tap, but running the tubing thru the die until reached the full depth so the leading end would be the full taper -- and it's _still_ larger than the tapped hole into which it's to go so can't get it started... And, as noted above, tested w/ a new 1/8" nipple w/ same result as well as easily started the tubing in a 1/8" coupling so it's not that the die is large...it is some still yet to be determined thread on the original 'cuz I can rethread the cut off end easily into the hole from whence it came. I'll try a lamp nipple this morning and see if it is that by any chance't -- seems a really weird choice if so... -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/18/2013 8:31 AM, dpb wrote:
.... I'll try a lamp nipple this morning and see if it is that by any chance't -- seems a really weird choice if so... Nope--same problem: it's too large to go into the tapped hole, simply spins in the opening w/o enough inside to catch a thread. This is truly bizarre piece o' engineering...thanks B&S! A 3/8" tap is also large as well as a 1/8" NPT -- they could be forced but won't start to follow the existing threads. I've no idea what it must have been. I contacted B&S; guess we'll see if they'll respond. I've also ordered a new tube; they're pretty cheap...if the replacement is also long I'll modify on the non-threaded end instead altho maybe they're now shorter to match up w/ the replacement carb location. -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/18/2013 5:44 AM, Jim Wilkins wrote:
wrote in message ... On 6/17/2013 6:31 PM, Jim Wilkins wrote: wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad ... You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... What's the chance that it is 3/8-16 or 3/8-24? ... Zero. Thread pitch is more like 27-28 -- my eyes/bifocals aren't good enough over the length of the section to tell it from a 1/8" NPT as said which is 27. Problem is, a new 1/8 nipple doesn't fit either so it's not that the die I'm using is off... -- 3/8-27 (1/8IPS) is the standard thread for lamp fittings. http://www.grandbrass.com/help.cfm Yeah, thanks, hadn't thought of that before you and another poster noted it. But, I tried a lamp nipple this morning -- no joy; still larger than the tapped hole (and the threaded end of the original tube end). -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/17/2013 8:40 PM, PrecisionmachinisT wrote:
wrote in message ... On 6/17/2013 6:27 PM, PrecisionmachinisT wrote: wrote in message ... On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... 9mm 1.25 is a fairly common metric thread. But 9 mm is only .315 No that is 8mm. 9 mm = 354 Right...obviously hit the "right next door" key on the calculator and didn't notice. But still .354 is well under the .370 or so of the subject thread OD on the tubing. -- |
What's just slightly smaller OD than 1/8" NPT thread????
On Tue, 18 Jun 2013 08:31:45 -0500, dpb wrote:
On 6/18/2013 5:41 AM, Lloyd E. Sponenburgh wrote: DPB: I ran the NPT all the way thru Ya THINK that might mess up the taper? nahhh... it's just there for pretty, right? I, personally, don't own any tapered pipe taps that can be run all the way through the stock.... Not talking about a tap, but running the tubing thru the die until reached the full depth so the leading end would be the full taper -- and it's _still_ larger than the tapped hole into which it's to go so can't get it started... And, as noted above, tested w/ a new 1/8" nipple w/ same result as well as easily started the tubing in a 1/8" coupling so it's not that the die is large...it is some still yet to be determined thread on the original 'cuz I can rethread the cut off end easily into the hole from whence it came. I'll try a lamp nipple this morning and see if it is that by any chance't -- seems a really weird choice if so... The really SIMPLE fix is to run the 1/8" NPT tap into the hole and the insert the fitting, not????? |
What's just slightly smaller OD than 1/8" NPT thread????
On Tue, 18 Jun 2013 10:52:35 -0500, dpb wrote:
On 6/18/2013 8:31 AM, dpb wrote: ... I'll try a lamp nipple this morning and see if it is that by any chance't -- seems a really weird choice if so... Nope--same problem: it's too large to go into the tapped hole, simply spins in the opening w/o enough inside to catch a thread. This is truly bizarre piece o' engineering...thanks B&S! A 3/8" tap is also large as well as a 1/8" NPT -- they could be forced but won't start to follow the existing threads. I've no idea what it must have been. I contacted B&S; guess we'll see if they'll respond. I've also ordered a new tube; they're pretty cheap...if the replacement is also long I'll modify on the non-threaded end instead altho maybe they're now shorter to match up w/ the replacement carb location. Exactly what hole, fitting, and tube are we talking about here?? |
What's just slightly smaller OD than 1/8" NPT thread????
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What's just slightly smaller OD than 1/8" NPT thread????
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What's just slightly smaller OD than 1/8" NPT thread????
On 6/17/2013 18:56, dpb wrote:
On 6/17/2013 5:25 PM, Jim Wilkins wrote: wrote in message ... Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? -- http://www.carbidedepot.com/formulas-tap-standard.htm http://www.carbidedepot.com/formulas-tap-pipe.htm http://www.engineersedge.com/hardwar...pe-threads.htm You do this stuff by guesswork?? Pretty much, yeah... :) All of those show a 1/8" NPT which won't go into the threaded hole. The question is what is there that is somewhat smaller? I found zilch other than a BPS which seems really odd it would have been used on a 1980's vintage B&S engine... -- What part is it? HP rating? Vertical or horizontal shaft? Millions of B & S engines built. Used parts very cheap. -- Steve Walker (remove brain when replying) |
What's just slightly smaller OD than 1/8" NPT thread????
On Tue, 18 Jun 2013 19:13:43 -0500, dpb wrote:
On 6/18/2013 7:03 PM, wrote: Nope--same problem: it's too large to go into the tapped hole, simply spins in the opening w/o enough inside to catch a thread. This is truly bizarre piece o' engineering...thanks B&S! Breather tube on an old B&S 92905-1825 engine. #11 on following diagram...the RH end that looks funky in the drawing is threaded--that's the thread in question. http://www.jackssmallengines.com/Jacks-Parts-Lookup/Model-Diagram/briggs-stratton/139156/25762 It sure sounds like an R 1/8 thread; a British tapered pipe thread. They're common on Japanese and European pneumatic components, and behave exactly as you describe when you try to thread a 1/8 NPT male into an R 1/8 female - you less than a turn of engagement. I have no idea why an R thread would turn up on an old B&S engine, unless perhaps the carb was made overseas. The pic in the link looks a lot like the carbs on the cast iron engines we had on our go-karts circa 1965, and the motors were not new then. -- Ned Simmons |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 8:50 AM, Ned Simmons wrote:
On Tue, 18 Jun 2013 19:13:43 -0500, wrote: .... Breather tube on an old B&S 92905-1825 engine. .... It sure sounds like an R 1/8 thread; a British tapered pipe thread. They're common on Japanese and European pneumatic components, and behave exactly as you describe when you try to thread a 1/8 NPT male into an R 1/8 female - you less than a turn of engagement. I have no idea why an R thread would turn up on an old B&S engine, unless perhaps the carb was made overseas. The pic in the link looks a lot like the carbs on the cast iron engines we had on our go-karts circa 1965, and the motors were not new then. Not sure about the provenance of the original carb--it has no independent markings that I can tell as to origin. I had presumed that at that point in time would still have been US. This dates from 1980; I've got the original paperwork from Dad still so that's not a guess. It's old but has _very_ few hours but for some reason over the winter a year ago it developed a warped base for the carb (that is formed into top of gas tank) and haven't been able to solve that issue so was putting a conversion kit that replaces it w/ the current style. As noted above, the Brit pipe thread was the only thing I had been able to find that looked to be just that tiny bit smaller enough but not too much but as you say seems bizarre if so. I _think_ from playing from both sides(+) that it isn't actually tapered, though--I found a reference also to a British straight thread of same diam/pitch as well so I'm guess maybe that's what it is. (+) ie, I can start the original threaded cutoff section into the mating opening in the block from either side. I'd have thought if tapered it wouldn't want to start from the back side. Wonder what chances are of finding one of them for a reasonable price??? Initial looking wasn't much success, surely, and definitely there's not going to be anybody in a small town in SW KS w/one (or likely anybody who's even heard of it). -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/17/2013 23:26, dpb wrote:
Got a what mic's at just under 3/8" 0D 0.374 or so Al tube w/ a threaded end. Needed to shorten just a tad so just looking it looks like a 1/4" NPT to the naked eye so I just went ahead. Turns out that leaves it proud by enough can't get started into hole and can see the original is just enough smaller can see it is...anybody have any idea what that die size would have been to cut these? I ran the NPT all the way thru and took it to town and ran another die over it just to make sure wasn't a little over-sized. A search so far hasn't turned up any likely candidates; anybody here got any ideas? A NPT 1/4" thread that is made too small? It is really common to have mismatches between 1/4" NPT threaded parts. Especially pressure regulators and pressure gauges. Even quality companies like Tescom pressure regulator and Baumer pressure gauges - will only go about 1-2 turns to the 1/4" NPT thread. Also the difference in those NPT threads from different manufacturers seems to be same, so they have a good quality system producing the same (too small/big) NPT thread consistently. They are really NPT threads too, I have verified that as they never seem to match.. So, I'd use a 1/4" NPT tap to make the thread larger, if you think it is 1/4" NPT thread really.. |
What's just slightly smaller OD than 1/8" NPT thread????
On Wed, 19 Jun 2013 12:32:24 -0500, dpb wrote:
Wonder what chances are of finding one of them for a reasonable price??? I can't tell for sure what you mean by "one of them," but McMaster has a good selection of BSPT and BSPP fittings and adapters. -- Ned Simmons |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 1:24 PM, Ned Simmons wrote:
On Wed, 19 Jun 2013 12:32:24 -0500, wrote: Wonder what chances are of finding one of them for a reasonable price??? I can't tell for sure what you mean by "one of them," but McMaster has a good selection of BSPT and BSPP fittings and adapters. I was speaking of the BSPT and/or BSPP die...I'm thinking it probably doesn't matter terribly but the BSPP ("G" as opposed to "R", apparently) is what it likely must be. McM-C pretty much eliminates the "reasonable price", though... :) At least by my definition for a single use for this and again until I get the new tube in and see if it also needs munged upon. I did an eBay search and found a 100%-rated seller in China who'll ship one for free for $9 US but won't promise delivery for like 30 days. Best anything else I could find was in the $40 neighborhood and up (McM-C is $45; I had looked there already). I think I'll call machine shop here in town and see if there's any chance't they've got one -- I know him well enough he'd let me chase a set of threads if did. Tomorrow is the day three of the promised B&S response-time window--wonder what will find out from them, if anything. (Not holding breath, here on that one... :) ) -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 1:02 PM, Kristian Ukkonen wrote:
.... It is really common to have mismatches between 1/4" NPT threaded parts. Especially pressure regulators and pressure gauges. Even quality companies like Tescom pressure regulator and Baumer pressure gauges - will only go about 1-2 turns to the 1/4" NPT thread. Also the difference in those NPT threads from different manufacturers seems to be same, so they have a good quality system producing the same (too small/big) NPT thread consistently. They are really NPT threads too, I have verified that as they never seem to match.. So, I'd use a 1/4" NPT tap to make the thread larger, if you think it is 1/4" NPT thread really.. Guess I've never had the luck...ime the NPT matches fine. Then again, other than grease zerk nipples and a few other odds and ends there's almost no 1/8" pipe on the farm so I don't run into it that often. I really don't think these are NPT just owing to the lack of fit--I've about come to the conclusion of another that the likely culprit is the BSP(T/P, there I'm not yet conclusively convinced but leaning towards P) -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 21:41, dpb wrote:
On 6/19/2013 1:02 PM, Kristian Ukkonen wrote: It is really common to have mismatches between 1/4" NPT threaded parts. Especially pressure regulators and pressure gauges. Even quality companies like Tescom pressure regulator and Baumer pressure gauges - will only go about 1-2 turns to the 1/4" NPT thread. Also the difference in those NPT threads from different manufacturers seems to be same, so they have a good quality system producing the same (too small/big) NPT thread consistently. They are really NPT threads too, I have verified that as they never seem to match.. So, I'd use a 1/4" NPT tap to make the thread larger, if you think it is 1/4" NPT thread really.. Guess I've never had the luck...ime the NPT matches fine. Then again, other than grease zerk nipples and a few other odds and ends there's almost no 1/8" pipe on the farm so I don't run into it that often. My experience is with industrial parts, mostly AISI 316.. I really don't think these are NPT just owing to the lack of fit--I've about come to the conclusion of another that the likely culprit is the BSP(T/P, there I'm not yet conclusively convinced but leaning towards P) You are right, the BSPT is slightly smaller than NPT, but the thread pitch is also different.. NPT1/8"-27 vs BSPT1/8"-28.. Use a thread pitch gauge to verify? Nice chart: http://97.74.32.155/files/tchart.pdf |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 2:05 PM, Kristian Ukkonen wrote:
On 6/19/2013 21:41, dpb wrote: On 6/19/2013 1:02 PM, Kristian Ukkonen wrote: It is really common to have mismatches between 1/4" NPT threaded parts. Especially pressure regulators and pressure gauges. Even quality companies like Tescom pressure regulator and Baumer pressure gauges - will only go about 1-2 turns to the 1/4" NPT thread. Also the difference in those NPT threads from different manufacturers seems to be same, so they have a good quality system producing the same (too small/big) NPT thread consistently. They are really NPT threads too, I have verified that as they never seem to match.. So, I'd use a 1/4" NPT tap to make the thread larger, if you think it is 1/4" NPT thread really.. Guess I've never had the luck...ime the NPT matches fine. Then again, other than grease zerk nipples and a few other odds and ends there's almost no 1/8" pipe on the farm so I don't run into it that often. My experience is with industrial parts, mostly AISI 316.. I really don't think these are NPT just owing to the lack of fit--I've about come to the conclusion of another that the likely culprit is the BSP(T/P, there I'm not yet conclusively convinced but leaning towards P) You are right, the BSPT is slightly smaller than NPT, but the thread pitch is also different.. NPT1/8"-27 vs BSPT1/8"-28.. Use a thread pitch gauge to verify? If had one, would... :) Remember, I'm a farmer, not a machinist! :) To reiterate much of what has gone on above, I whacked the thread end off after to shorten because to a first glance for a 3/8" OD tube just presumed the thread would be 1/8" NPT and the existing pitch certainly is finer than a 3/8-24 as is easily visible by eye and w/ experience. I've tried to count/measure but the length is short enough and w/ my bifocals and that I don't have a digital mic I really can't tell whether the actual is 27/28. Given that the OD is too large w/ the NPT and the BSP is about the right diameter to solve the problem, I'm presuming it actually would be found to be 28 if did have the gauge. At present, the plan of attack is to await the replacement tube I ordered and hopefully they've also changed the dimensions to match the newer carb and I won't have to modify it. Failing that, I'll modify the unthreaded end instead even though means may have to change the bend some for alignment--that's why I chose the threaded, straight end to begin with. -- |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message
... On 6/19/2013 2:05 PM, Kristian Ukkonen wrote: ... Use a thread pitch gauge to verify? If had one, would... :) Remember, I'm a farmer, not a machinist! :) Oh. That explains a lot. The machinist in town may have a machine called a "lathe" that can cut most any diameter and pitch of thread you need, without taps or dies, if you don't mind paying him for the time it takes. http://i1.ytimg.com/vi/0q_q53wsyHU/hqdefault.jpg http://swarfrat.com/images/externalcut1.jpg 'Most' doesn't always include odd pipe thread pitches. Mine will cut 27 TPI, but it was meant for tool and instrument makers rather than general shop and repair work. jsw |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 15:44, dpb wrote:
On 6/19/2013 2:05 PM, Kristian Ukkonen wrote: On 6/19/2013 21:41, dpb wrote: On 6/19/2013 1:02 PM, Kristian Ukkonen wrote: It is really common to have mismatches between 1/4" NPT threaded parts. Especially pressure regulators and pressure gauges. Even quality companies like Tescom pressure regulator and Baumer pressure gauges - will only go about 1-2 turns to the 1/4" NPT thread. Also the difference in those NPT threads from different manufacturers seems to be same, so they have a good quality system producing the same (too small/big) NPT thread consistently. They are really NPT threads too, I have verified that as they never seem to match.. So, I'd use a 1/4" NPT tap to make the thread larger, if you think it is 1/4" NPT thread really.. Guess I've never had the luck...ime the NPT matches fine. Then again, other than grease zerk nipples and a few other odds and ends there's almost no 1/8" pipe on the farm so I don't run into it that often. My experience is with industrial parts, mostly AISI 316.. I really don't think these are NPT just owing to the lack of fit--I've about come to the conclusion of another that the likely culprit is the BSP(T/P, there I'm not yet conclusively convinced but leaning towards P) You are right, the BSPT is slightly smaller than NPT, but the thread pitch is also different.. NPT1/8"-27 vs BSPT1/8"-28.. Use a thread pitch gauge to verify? If had one, would... :) Remember, I'm a farmer, not a machinist! :) To reiterate much of what has gone on above, I whacked the thread end off after to shorten because to a first glance for a 3/8" OD tube just presumed the thread would be 1/8" NPT and the existing pitch certainly is finer than a 3/8-24 as is easily visible by eye and w/ experience. I've tried to count/measure but the length is short enough and w/ my bifocals and that I don't have a digital mic I really can't tell whether the actual is 27/28. Given that the OD is too large w/ the NPT and the BSP is about the right diameter to solve the problem, I'm presuming it actually would be found to be 28 if did have the gauge. At present, the plan of attack is to await the replacement tube I ordered and hopefully they've also changed the dimensions to match the newer carb and I won't have to modify it. Failing that, I'll modify the unthreaded end instead even though means may have to change the bend some for alignment--that's why I chose the threaded, straight end to begin with. -- $6.00 he http://www.repairclinic.com/PartDeta...230802/1651191 -- Steve Walker (remove brain when replying) |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 7:21 PM, Steve Walker wrote:
On 6/19/2013 15:44, dpb wrote: .... At present, the plan of attack is to await the replacement tube I ordered and hopefully they've also changed the dimensions to match the newer carb and I won't have to modify it. Failing that, I'll modify the unthreaded end instead even though means may have to change the bend some for alignment--that's why I chose the threaded, straight end to begin with. $6.00 he http://www.repairclinic.com/PartDeta...230802/1651191 Was $5 at JacksSmallEngines -- I did a fair comparison and per my usual experience Jack comes in either first or close enough I just stay at one place that has satisfied in the past... -- |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/19/2013 4:56 PM, Jim Wilkins wrote:
wrote in message ... On 6/19/2013 2:05 PM, Kristian Ukkonen wrote: ... Use a thread pitch gauge to verify? If had one, would... :) Remember, I'm a farmer, not a machinist! :) Oh. That explains a lot. The machinist in town may have a machine called a "lathe" that can cut most any diameter and pitch of thread you need, without taps or dies, if you don't mind paying him for the time it takes. .... I may be a farmer but I'm not an idiot... :( I'll presume the above was intended as an attempt at "dry" humor. Speaking of the machine shop I just had the shaft that had the discussion on whether anybody had any alternative bearing mounts a couple of weeks ago...that is on another project and used the machine shop budget for a while--certainly I'm not paying shop fees for this when I can get the new tube and start over for $5 plus postage. At worst I modify the other end; at best B&S will have modified the part to coincide w/ the currently available carburetor. -- |
What's just slightly smaller OD than 1/8" NPT thread????
On Wed, 19 Jun 2013 14:44:12 -0500
dpb wrote: snip At present, the plan of attack is to await the replacement tube I ordered and hopefully they've also changed the dimensions to match the newer carb and I won't have to modify it. Failing that, I'll modify the unthreaded end instead even though means may have to change the bend some for alignment--that's why I chose the threaded, straight end to begin with. Probably way too late... but I have a Briggs similar/like that. An old push mower with a 3.0 hp vertical shaft, mower blade bolts to crank. Probably built around the same time as yours. The carburetor gave me troubles from day one of my using it (it was already several years old). It had power problems, like it was running too lean. No oomph what so ever. It would bog down/stall out running at full throttle with very light grass. Took the carburetor apart several times before I finally figured it out. The plastic drop tube that goes from the carb down to the bottom of the tank has a metal ball inside it. Diagram part 611 (long) or 612 (short), "Pipe - Fuel" in the manual you have probably been looking at. I still have the Briggs Parts Manual pdf on my computer for this. Don't know if it is suppose to be a sort of check valve or limiter. But gas wasn't getting around it quick enough. Figured it out by trying to blow through it (ack, spit!) Carefully cut off the screen area at the bottom, took the ball out (maybe a bit smaller than a BB), used JB Weld to re-attach the screen. It has run GREAT since then. The difference was like night and day. That was maybe 7 years ago. It gets run for around 1.5 hours every time I mow the lawn to do the trim and places I can't get with the rider. Only took me a couple years to figure it out :) -- Leon Fisk Grand Rapids MI/Zone 5b Remove no.spam for email |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/20/2013 12:35 PM, Leon Fisk wrote:
On Wed, 19 Jun 2013 14:44:12 -0500 wrote: snip At present, the plan of attack is to await the replacement tube I ordered and hopefully they've also changed the dimensions to match the newer carb and I won't have to modify it. Failing that, I'll modify the unthreaded end instead even though means may have to change the bend some for alignment--that's why I chose the threaded, straight end to begin with. Probably way too late... but I have a Briggs similar/like that. An old push mower with a 3.0 hp vertical shaft, mower blade bolts to crank. Probably built around the same time as yours. The carburetor gave me troubles from day one of my using it (it was already several years old). It had power problems, like it was running too lean. No oomph what so ever. It would bog down/stall out running at full throttle with very light grass. ....[repair success story elided solely for brevity]... It has run GREAT since then. The difference was like night and day. That was maybe 7 years ago. It gets run for around 1.5 hours every time I mow the lawn to do the trim and places I can't get with the rider. Only took me a couple years to figure it out :) Glad to hear you got it figured out. This is 3.5 iirc but quite similar. The problem w/ this one is that it's leaking past the diaphragm gasket where it's not supposed to be because the top of the tank warped (into which is also formed the base of the carb as you're aware). You can manage to adjust it so it will run at full throttle but can't throttle down at all or it just floods out. Trying to flatten on diamond plate wasn't all that successful. :( It seemed/seems really weird that it did that after some 30 yr being stored the same way in the same place all those years. It was working perfectly the last time in the previous fall and had the full-blown symptom first start the next spring. Like yours, it is only used for trimming around after the ZTR to clean up in the little spots. Probably about the same amount of time per use so despite the age it really has very few hours on it. -- |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message
... On 6/20/2013 12:35 PM, Leon Fisk wrote: ... The problem w/ this one is that it's leaking past the diaphragm gasket where it's not supposed to be because the top of the tank warped (into which is also formed the base of the carb as you're aware). You can manage to adjust it so it will run at full throttle but can't throttle down at all or it just floods out. Trying to flatten on diamond plate wasn't all that successful. :( Thick bead of silicone? |
What's just slightly smaller OD than 1/8" NPT thread????
On 6/20/2013 3:59 PM, Jim Wilkins wrote:
wrote in message ... On 6/20/2013 12:35 PM, Leon Fisk wrote: ... The problem w/ this one is that it's leaking past the diaphragm gasket where it's not supposed to be because the top of the tank warped (into which is also formed the base of the carb as you're aware). You can manage to adjust it so it will run at full throttle but can't throttle down at all or it just floods out. Trying to flatten on diamond plate wasn't all that successful. :( Thick bead of silicone? We thought of that or similar but can't figure out how you'd get it where it needs to be and still keep it out of the holes where it can't go... -- |
What's just slightly smaller OD than 1/8" NPT thread????
"dpb" wrote in message
... On 6/20/2013 3:59 PM, Jim Wilkins wrote: wrote in message ... On 6/20/2013 12:35 PM, Leon Fisk wrote: ... The problem w/ this one is that it's leaking past the diaphragm gasket where it's not supposed to be because the top of the tank warped (into which is also formed the base of the carb as you're aware). You can manage to adjust it so it will run at full throttle but can't throttle down at all or it just floods out. Trying to flatten on diamond plate wasn't all that successful. :( Thick bead of silicone? We thought of that or similar but can't figure out how you'd get it where it needs to be and still keep it out of the holes where it can't go... Put plastic film under the carb. Once the silicone hardens carve it to shape. I've done that with epoxy but it's tricky to time the range where it holds its form but is still soft enough to whittle. That job gave me a bad opinion of the rapid-prototype plastic I was repairing. jsw |
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