Correct starting diameter for an external thread.

May 14, 2007 5 Replies

I'm familiar with the idea of drilling the correct size hole prior to using a tap to thread the hole but what about using a die for an external thread?



I need something (a length of rod) to have an M6 thread on it. The rod is nominally 6mm in diameter. Do I just use the die on the rod "as is"?



TIA



Brian


Yes correct.

.

-- Regards,

John Stevenson Nottingham, England.

Visit the new Model Engineering adverts page at:-

formatting link

at:-

formatting link
you try that with a manual die holder and the rod will end up looking like a snake..........

has to be help rigidly in a tailstock die holder....no give ... or the dies can only be used for going over threads to tidy them up once cut on a lathe.

all the best.mark

Why not just buy a piece of threaded rod. How long does it have to be.

Must admit that I tend to take the rod just a breath under size and start the thread on the lathe then finish off with a die nut. Even so everythng needs to be rigid.otherwise the die just rips off bits of metal.

On or around Mon, 14 May 2007 20:49:19 GMT, "Brian Reay" enlightened us thusly:

yep. I find it helps to make a chamfer on the end, at about 30 degrees, taking the diameter of the end of the rod down to about the core diameter of the thread you intend to cut, about 4.8mm on M6x1.0.

if using a hand die-holder, you need to take exception pains to hold it perpendicular to the rod to start it.

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required