cropping screwed rod

[adrianhastings]

Hi, I need some advice on the design of a cropping tool for cropping M3 screwed rod (316 stainless)that will leave the ends relatively undamaged. We have a need for several thousand parts and intended parting them off on a CNC lathe, this proved problematic so we are thinking of cropping them to length but we would obviously like to avoid dressing the ends if we can. Any ideas anybody?

 

[ornerynorsk]

Generally, in hardware manufacturing, thread rolling is done AFTER length operations, which is why threads do not have to be re-chased. I have seen thread-shears where the rod or the part to be threaded is actually threaded through the die, and sheared flush, but you are still going to have some distortion. Abrasive cutoff using a very fine wheel WHILE rotating the stock would give very satisfactory results, but it is more labor intensive.

 

[mepl]

Unfortunately, most manufacturers "rumble" or vibrate hundreds of such components together for a few hours to de-burr threads. The pitfall with this secondary operation is percentage damge to the crests of threads in softer materials.

 

[ornerynorsk]

If you have several 1000, why not just have them made up for you in the length you need? There are many hardware shops equipped to do this. Is the part in question a stud or a headed part?