.268-40 tap and die ?

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jcfx
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.268-40 tap and die ?

Post by jcfx »

I have a EMCO toopost grinder for my V10P lathe that I'm doing a little refurbing on
and come to discover that the spindle for the TP grinder is WW spindle for a Unimat.
I'd like to attempt to make new grinding wheel arbors for the spindle and I'm looking for
an odd siize tap and die.
I think it's a .268 -40 thread, does any one know of a source other than eBay for such an odd
tap and die ?
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liveaboard
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Re: .268-40 tap and die ?

Post by liveaboard »

Drill it out and put in a 1/4" helicoil?
jscarmozza
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Re: .268-40 tap and die ?

Post by jscarmozza »

That may be an ASME #16, obsolete and out of production for a long time. I took a quick look through my oddball taps and don't have anything like it. Liveaboard may have the answer.
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mcostello
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Re: .268-40 tap and die ?

Post by mcostello »

Victor Tools sells odd ball taps.
jcfx
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Re: .268-40 tap and die ?

Post by jcfx »

Liveaboard, I don't think that'll work, the drawbar is 8mm OD doing that ( 1/4" helicoil or tap ) is going to leave me a
an awfully thin wall.
It may be obsolete, I'm still pounding the intarwebs for info on Unimat's an other watch makers lathes
like Boley that made 8mm collets.
Looked thru Victors offering, nothing available.
John Evans
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Re: .268-40 tap and die ?

Post by John Evans »

JCFX Give Larry Vanice over on PM a shout as he is heavily into watch makers lathes etc.
www.chaski.com
Rich_Carlstedt
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Re: .268-40 tap and die ?

Post by Rich_Carlstedt »

That is really close to a 7 mm -.65 thread (.275 - 39)
There is a 9/32 (.281) x 40 thread called a Model Engineer Thread
You can check it out here
https://www.tap-die.com/contents/en-uk/ ... 40tpi.html
Rich
In the old days , many manufacturers had their own threads , so they could sell spare parts
whateg0
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Re: .268-40 tap and die ?

Post by whateg0 »

How hard would it be to just turn a new spindle with a common thread if that one turns out not to be the m7 suggested?
jcfx
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Re: .268-40 tap and die ?

Post by jcfx »

Rich, that's a good site for oddball taps, too bad they're in the UK.

whateg0, probably not hard, it's time thats' the issue, I'm inbetween gigs and there's
other shop maintenence /cleanup I need to do. Besides I've revisted threading on my lathe
and it's seriously pissing me off.
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Bill Shields
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Re: .268-40 tap and die ?

Post by Bill Shields »

Were the original parts made in Europe?
If originally for a unimat...would bet $ of tap that it is not imperial.

Suggest you just get the 7 x .65 tap and see if it will run into the existing arbor
Too many things going on to bother listing them.
jcfx
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Re: .268-40 tap and die ?

Post by jcfx »

Bill, Yes the parts are European, EMCO, they made both the Unimat and the Maximat series lathes,
the best I can figure is that they used the watchmakers Unimat lathe spindle for the toolpost grinder
accesory for the Maximat lathes. Watchmaker collets seem to have their own threads for the collets
and arbors, this is based on a Sherline pdf I found on their site, it's kind of wacky, an 8mm ( .315 ) collet body
will have different pitch threads depending on who makes them ( Lorch is .275-40, Boley .268-40 ) and none are
spec'd in metric.

I'm starting to hit dead ends so I may just order a tap and die off ebay and wait months for it arrive.
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Bill Shields
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Re: .268-40 tap and die ?

Post by Bill Shields »

AH...well...there is another option out there.

use the existing drawbar for the arbors that you have and make a new drawbar, using an available thread -> for new arbors...
Too many things going on to bother listing them.
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