I need to thread about 20 lengths of steel rod with 20mm of M6 at each end, no lathe or anything, just a handheld die stock with an HSS die. Mild, Silver & 303 Stainless Steels seem to be the most commonly available stock - are any or all suitable for threading by hand? Thanks.
Stainless will be hard work and probably kill a few dies. Silver steel threads like a dream, mild steel is pretty easy too. Plenty of Trefolex or Temaxol cutting paste on the end and in the die will make life easier. I'd be tempted to cut twice, once with the die open, the second with it clamped down, will make a nicer thread, especially on mild steel which has a tendancy to go a bit dog eared on the peaks.
I would certainly shy away from stainless or silver steel. The biggest problem is keeping the die/holder square to the rod. Difficult without a lathe.
Could alway look for a small local engineering firm, to do the job,shouldn't cost more than a few pints.
Free cutting stainless isn't a problem. A google will bring up what grades are. A decent hss die is best. John -
Thanks for the replies. I'm assuming that with the harder materials a decent chamfer / lead will be required & maybe be best done with a grinder?
...and when cutting I would go for two turns and then back off a third to break the chip. Lead in pretty important or you'll have trouble getting it started or straight, not much needed; with mild steel a file will do.
Probably best to put them in a drill and use a file unless you have a lathe. If the chamfer isn't even with the diameter you'll have problems running the die on square to the rod - what ever material you use. If dies or taps use 3 flutes / cutting edge they should be reversed every 1/3 of a turn to break the chip. Half or one turn is usually ok. You'll probably need to do over 1 turn when making the first cut on the end. John -
In the absence of a lath I find putting the piece in a cordless drill and running it slowly against a bench grinder wheel at about 15-20 degrees gives a reasonably accurate chamfer. You will never get the die 100% on square by hand, but over a short thread it shouldn't notice with care. As john says reverse the die frequently and clean out all the swarf from it between uses.