Thread Cutting?

Anybody got a link to a good thread cutting tutorial? Also, when machining both the male and female items to be threaded, how much clearance do you allow to start with between the two?

Reply to
Grady
Loading thread data ...

I just made female threads on the lathe for the first time. I used a boring bar with a 60 degree bit that I ground.

I have a book "Machining Fundamentals" by John R. Walker that explains how to grind the bits and operate the lathe to make the cuts.

I ignored the book and made some >Anybody got a link to a good thread cutting tutorial? Also, when machining

Reply to
Clark Magnuson

Not exactly an answer to you question, but if possible, as you approach finished thread depth, stop and test fit (without taking the part out of the chuck). Then just take light passes until the fit is what you want it to be by feel. Make sure the thread are clean when you do this.

Of course, this does not work when one part already exists and is too big to bring near the lathe. Also, I'm assuming this is hobby work and the exact clearance is not critical.

-Greg

Reply to
Greg

Umm. I did that the first time too.

Jim

Reply to
jim rozen

Second that, Clark! "Walker" is a great book but not quite correctly named. From the standpoint of my limited machining experience, he covers a lot more than fundamentals. Great book.

Reply to
Robert Swinney

...me too.

Gunner

It's better to be a red person in a blue state than a blue person in a red state. As a red person, if your blue neighbors turn into a mob at least you have a gun to protect yourself. As a blue person, your only hope is to appease the red mob with herbal tea and marinated tofu.

(Phil Garding)

Reply to
Gunner

"When all else fails, but only then, try following the printed directions." :-)

Ted

Reply to
Ted Edwards

I read the books I could find and still couldn't figure it out till I threw the books aside and said screw it, it looks like I'm just going to have to wing it and it worked the first time !

I'm perplexed that in the information age why computers are like stabbing in the dark.

Reply to
Sunworshipper

That's what I do, try it. Lately, I'm cutting an internal sort of acme thread, 3/4" x 5tpi. "Sort of" because it is intended to fit mop handles, and they are NOT precise, at least to thread form, depth, etc. So I chopped off a $1.95 broom handle with a metal tip to test, then removed and tested on another handle with a plastic tip. Oops, have to break the edge and open up the i.d.

Picking up the thread again wasn't too bad. I just stuck the piece back in the collet, engaged the tool in the thread with the crossfeed with the boring bar loose and the threading dial at the right spot, then clamped the boring bar. To set the threading dial, I disengaged the drive and rotated the spindle (with the tool retracted out of the threads, of course).

I followed a suggestion I believe I read here a while back, and threaded in reverse on the back side. It worked very well, because the carriage travel was left to right, or out of the bore. At 5 tpi, it moves pretty quick, even in back gear.

Pete Keillor

Reply to
Peter T. Keillor III

Machinery's Handbook, or any other machinist's handbook will give you exhaustive information on thread turning. In general, I use a couple of thou. for clearance, but it makes a very tight fit. The class of the thread, based on strength requirements and size determines the clearance. It's a good idea to stick with published standards for interchangeability. Bigs

Reply to
Bugs

What's an even better idea is to learn to properly apply thread wires so you can stick to the standards. They are of no use for internal threads, but perfect for outside measurements, and cheap to own. For those that don't understand, wires are the proper way to measure threads, and are used for calibrating thread gages. There is no better method.

Harold

Reply to
Harold and Susan Vordos

I have some information on using three wires on my web pages

formatting link
formatting link
These web pages have been shamefully neglected for far too long but I plan to converto to a "rreal" web presence soon and will update and improve things on the pages.

Errol Groff

Instructor, Machine Tool Department

H.H. Ellis Technical High School

643 Upper Maple Street Dantieson, CT 06239

New England Model Engineering Society

formatting link

Reply to
Errol Groff

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.