threading a 1/2 hole useing acme thread

[irishwoodsman]

has anyone threaded a hole useing a lathe with a acme thread the hole is a 1/2 inch diameter or is it better to use a tap thanks:thinking:

 

[Tony Wells]

Depends on the pitch, the length, and how many. Probably a tap.

 

[irishwoodsman]

1/2x8 is the size and its left handed:biggrin: acme thread

 

[irishwoodsman]

wow small boring bar mmm will have to think about this lol thanks for the info. mac:biggrin:

 

[llarson]

I've done some 3/4" acme thds; quite difficult because of tight space. I had opportunity to do a 3/4-8 at work this week using a "tandem tap", rough and finish on one stem, fun to do. That was the first acme tap I have seen other than in pictures. If you try it with a boring bar, make it a real rigid one, the tool pressure is a bunch. Then too, one has to justify the cost. Good luck and let us know how it came out.

 

[irishwoodsman]

will due, i got some really small bars and i know its going to be slow going:thinking:

 

[Tony Wells]

I know we all like to prove our independence, but sometimes it's just not worth it. Is this nut something that could be bought? Making one is possible, with a tap being the easiest way, but by far more expensive than single pointing it. BUT, a tap for one piece? Impractical. I guess it wouldn't cost much to try to machine your own, and if that doesn't work out, or you don't have the time to do it, then go shopping.

 

[irishwoodsman]

i got time, lol the nut is for the cross slide its 1/2x8tpi i bought a new screw and nut for my lathe and after some filing mod it works great but the only draw back is , i didnt make it, they say a lathe can make its own self other than the casting, but i dont need another lathe just a few extra parts i made lol, they say dont try to thread a hole smaller than 3/4 but some guys are doing it, plus i cant find a 1/2x8 left hand acme tap:thinking:

 

[irishwoodsman]

understand:biggrin:

 

[pdentrem]

What about making your own tap? Since it is a brass nut, a steel tap does not to be hard to cut. Just sharp. Make a rougher and a finisher seperately and bore the hole to the right ID. You can leave a pilot on the tap, that fits the bored hole and controls the tap as it enters the brass nut.