Can I retap a 1/2" 24tpi UNF female thread -> M12?

[HiltonSteve]

Why not buy (or borrow) a 1/2" UNF bolt, cut the head off then drill it out to suit your stepper then put in a couple of grub screws in to hold it place.

JD!

[HiltonSteve]

Thinking about it, leave the head on then you can screw the chuck up to it and also put the grub screws through the flats on the head.

[HankMcSpank]

Why not buy (or borrow) a 1/2" UNF bolt, cut the head off then drill it out to suit your stepper then put in a couple of grub screws in to hold it place.

JD!

Super idea.... I guess some folks know how to go about this the right way & some folks don't (I'll be in the latter camp - so thank heavens for forums like this!)

(BTW: For once, I already have some suitable 1/2" 24tpi bolts!)

[John S]

Are you sure it's 1/2" x 24 ?

Most chucks I have seen are 1/2" x 20 UNF
BTW Steve if you 'borrow' a bolt what happens when the guy wants it back and you have gronched it up ? :question::question:

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[HiltonSteve]

I was basing the "borrow" coment on what people say to me when they want to "borrow" something, nine times out of ten I never see it again....!

[HankMcSpank]

Are you sure it's 1/2" x 24 ?

Most chucks I have seen are 1/2" x 20 UNF
BTW Steve if you 'borrow' a bolt what happens when the guy wants it back and you have gronched it up ? :question::question:

.

It's great to nestle in the bosom of those that know.

I went and checked what I'd bought, transpires I bought a 10mm chuck (not a 13mm chuck)

http://cgi.ebay.co.uk/ws/eBayISAPI.d...lenotsupported

"3/8" x 24 thread."


Fortunately, the bolts I have were specifically bought for it at the time (a failed idea that I had, that I can now re-use these bolts for)