'hand' die cut threads ; 1/2" NC .... ??how??
Readership ,
How do you hand-cut 1/2" NC( 13tpi ) with a plain vanila tap & die set ??? Whats the 'secret' to geting the 'die' started properly ??? cold rolled rnd stock. Ed |
'hand' die cut threads ; 1/2" NC .... ??how??
"0_Qed" wrote in message ... Readership , How do you hand-cut 1/2" NC( 13tpi ) with a plain vanila tap & die set ??? Whats the 'secret' to geting the 'die' started properly ??? cold rolled rnd stock. Ed Dies are a bitch to use, plain and simple. If your die is adjustable, open it up so you take two passes, one to rough the thread, one to take it to size. Cut or grind a chamfer on the end of your material, and make sure it's uniform, so it assists in starting the die, not only square, but concentric with the material. Also, make sure the material isn't oversized. If you're trying to thread hot rolled stock, it's often out of round and oversized. While I'm not a fan of reducing the major diameter of threads, you could cut the material undersized by ..012" and still be in tolerance for a class 2 thread. Don't permit the die to start crooked with the idea you'll get it to run straight once started. That works about as well as a pig on stilts. Best bet is to use a lathe and chase the thread, even if you use a die to take it to size after roughing it oversized.. By roughing with a lathe (single point threading), the thread will be at right angles to the material, so the die will follow and yield a somewhat better thread than if you used the die alone. Hope that helps---- Harold |
'hand' die cut threads ; 1/2" NC .... ??how??
Harold and Susan Vordos wrote:
.... If your die is adjustable, open it up so you take two passes, one to rough the thread, one to take it to size. Cut or grind a chamfer on the end of your material, and make sure it's uniform, so it assists in starting the die, not only square, but concentric with the material. .... A few times I've left some extra length, turned to root diameter, to start a die out straight, and conversely when tapping, drilled a little ways at ridge-diameter size to start a tap straight. Home shop expedients ... Don't permit the die to start crooked with the idea you'll get it to run straight once started. That works about as well as a pig on stilts. .... I've never seen a pig on stilts so couldn't say. Your varied experience never ceases to amaze me! -jiw |
'hand' die cut threads ; 1/2" NC .... ??how??
Harold and Susan Vordos wrote:
Dies are a bitch to use, plain and simple. Yup. Cowardly, I gave up, went to the local Fastenal store, bought 'B7' threaded rod & nuts. If your die is adjustable, Solid. tear ....anip... Many thanks for the replys. Ed |
'hand' die cut threads ; 1/2" NC .... ??how??
I agree with the other posters about chamfering the end, to about 45
degrees, down to the root diameter of the thread or even a little less. I do have a lathe, so I chuck the stock to be threaded, lock the chuck, apply the die/ die stock to the work and use the tailstock ram to gently push and align the die with the stock. If you have enough hands, you can crank the tailstock ram gently as you begin threading. If you can't do both, turn a little, bring tailstock ram up, turn a little more, etc.. I keep the "pressure" on for about 2 turns. This has worked well for me for many years, even up to 3/4-10. Without a lathe, maybe you can use this general idea to make a simple fixture to do the same thing. Clamping the stock vertically, pointing up through your drill press table comes to mind. Needless to say , you need a sharp die and not one of those rethreading dies that are just used for cleaning up an existing thread. Pete Stanaitis 0_Qed wrote: Readership , How do you hand-cut 1/2" NC( 13tpi ) with a plain vanila tap & die set ??? Whats the 'secret' to geting the 'die' started properly ??? cold rolled rnd stock. Ed |
'hand' die cut threads ; 1/2" NC .... ??how??
"0_Qed" wrote in message ... Harold and Susan Vordos wrote: Dies are a bitch to use, plain and simple. Yup. Cowardly, I gave up, went to the local Fastenal store, bought 'B7' threaded rod & nuts. Smart move, actually. Cut threads are woefully lacking in strength as opposed to rolled threads, plus the surface finish and form is often questionable. Harold |
'hand' die cut threads ; 1/2" NC .... ??how??
As an alternative to this but basically the same idea is to grind 3 flats
spots so you can hold the stock FIRMLY in a jacobs chuck in the tail stock, Stick the die in the lathe chuck (3 jaw works nicely for hex dies collet works well for round ones) and run the stock through that way. I do a LOT of threading of 1/4 brass with 5-40 and I can make 'all thread' like you wouldn't believe this way under power... I also have a small collet holder I can put in the tailstock so holding up to 1/4 is a breeze. --.- Dave "spaco" wrote in message ... I agree with the other posters about chamfering the end, to about 45 degrees, down to the root diameter of the thread or even a little less. I do have a lathe, so I chuck the stock to be threaded, lock the chuck, apply the die/ die stock to the work and use the tailstock ram to gently push and align the die with the stock. If you have enough hands, you can crank the tailstock ram gently as you begin threading. If you can't do both, turn a little, bring tailstock ram up, turn a little more, etc.. I keep the "pressure" on for about 2 turns. This has worked well for me for many years, even up to 3/4-10. Without a lathe, maybe you can use this general idea to make a simple fixture to do the same thing. Clamping the stock vertically, pointing up through your drill press table comes to mind. Needless to say , you need a sharp die and not one of those rethreading dies that are just used for cleaning up an existing thread. Pete Stanaitis 0_Qed wrote: Readership , How do you hand-cut 1/2" NC( 13tpi ) with a plain vanila tap & die set ??? Whats the 'secret' to geting the 'die' started properly ??? cold rolled rnd stock. Ed |
'hand' die cut threads ; 1/2" NC .... ??how??
That works about as well as a pig on stilts. Now THAT is a visual that I would pay some big bucks to see. But only in person...video looses too much. Mike |
'hand' die cut threads ; 1/2" NC .... ??how??
According to 0_Qed :
Readership , How do you hand-cut 1/2" NC( 13tpi ) with a plain vanila tap & die set ??? Whats the 'secret' to geting the 'die' started properly ??? cold rolled rnd stock. Some die stocks (wrenches) have an adjustable guide on the other side which will help get the die started straight onto the workpiece. However -- have you checked the dimensions of the cold rolled stock? I think that it typically is a little oversized to allow machining to final size. This makes it more difficult to thread in any case. If you had a lathe, you could trim the OD to the proper size, and could also turn the end to the minor diameter for 1/8" or so to help get the die started straight. If your dies are hexagonal shaped, they are probably rethreading dies -- used for cleaning up damaged threads, and not for generating new threads. "tap and die sets" are often supplied with these -- and with only carbon steel taps. Round dies, with a slot to the center and a screw for adjusting the size are more likely to produce good threads, and these should be marked "HSS" (High Speed Steel). You don't say *which* cold rolled steel -- some steels are easier to thread (and to otherwise machine) than others. You don't say whether you have used any cutting fluid. Go to the Home Depot and check around for a blue bottle of "Rigid" high sulfur cutting oil -- usually in the plumbing department. It will stink, but it will improve the quality of the threads. In any case -- you need to back up the die about every 1/4 turn to break off the chips to keep them from clogging the die. (This is even more important for taps, which have smaller recesses (flutes) to allow the chips to accumulate. Good Luck DoN. P.S. For whatever reason, everything except your original article seems to be marked as expired. I can probably bring them back later, but not while in the middle of the newsreader. So -- I don't know what others have replied. -- 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 --- |
'hand' die cut threads ; 1/2" NC .... ??how??
DoN. Nichols wrote:
Some die stocks (wrenches) have an adjustable guide on the other side which will help get the die started straight onto the workpiece. ....snip... Many thanks for the reply. "Off" to find rnd, adjustable die(s) and holder, and cutting fluid. Ed |
'hand' die cut threads ; 1/2" NC .... ??how??
0_Qed wrote:
... Whats the 'secret' to geting the 'die' started properly ??? .... Take a small piece of steel or aluminum, 3/4" thick is good, 1/2" would be OK. Drill a 1/2" hole in it. Slip this piece over your stock and clamp your die stock to it. I have a piece with holes for all the sizes that I die-thread. Won't work if your piece to be threaded is too short. Bob |
'hand' die cut threads ; 1/2" NC .... ??how??
OR use a tail stock die holder. Even if you just remove the tail center
and hod the die in a stock and use the flat face of the TS ram to position and hold the die against the work, you should get fairly close to a true thread. Other advise about opening the width of an adjustable die and tapering end of stock also good. On Wed, 12 Apr 2006 20:12:22 -0700, "Harold and Susan Vordos" wrote: Best bet is to use a lathe and chase the thread, even if you use a die to take it to size after roughing it oversized.. By roughing with a lathe (single point threading), the thread will be at right angles to the material, so the die will follow and yield a somewhat better thread than if you used the die alone. |
'hand' die cut threads ; 1/2" NC .... ??how??
Bob Engelhardt wrote:
0_Qed wrote: ... Whats the 'secret' to geting the 'die' started properly ??? ... Take a small piece of steel or aluminum, 3/4" thick is good, 1/2" would be OK. Drill a 1/2" hole in it. Slip this piece over your stock and clamp your die stock to it. I have a piece with holes for all the sizes that I die-thread. Won't work if your piece to be threaded is too short. Wow! You've invented the multiple sized colleted die holder. BugBear |
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