Jet bench grndr spndl nut specs?

I recently came across a oneway wheel balancing system
for grinders with a 1/2" spindle. Unfortunately, the spindle
on my old Jet 6" grinder is a bit too short (1/8" or so).
I was thinking oneway I could make things work would be to
use thinner nuts on the ends of the spindle.
Another way would be to machine the ends of the flange pieces
down by about 0.160", which will still allow a 1" wide wheel
to be used.
What are the specs on those nuts?
I know one is RH- and one is LH-threaded, and I think both
are 1/2" diameter. I measured 12 threads per inch with my
(std) gauge, but the common course thread 1/2" nuts are 13 tpi.
The closest metric size would be M12x2.0, but again the
thread pitch is funny. Most M12 are 1.25, 1.5, or 1.75mm
per thread. Maybe it's 1.75 ?
Any one know this spec for sure and even better where I
might find a high grade, thinner, LH nut like this?
I could also machine the existing nuts thinner, but I'd
rather use a higher grade, thinner one.
Thanks for any suggestions.
Jeff Dantzler
Reply to
Jeff Dantzler
Loading thread data ...
The Chinese apparently looked in their old copy of Machinery's Handbook and noted that 1/2-12 is a US standard size, and comes before 1/2-13 in the list. They must have then assumed that because it was listed first, it is the preferred thread. Otherwise there is no explanation for them using that thread in so much of the equipment they export to the US.
Reply to
Gary Coffman
"Jeff Dantzler" wrote: (clip) I measured 12 threads per inch with my (std) gauge, but the common course thread 1/2" nuts are 13 tpi.(clip) ^^^^^^^^^^^^^ The outboard spindle thread on my Jet woodlathe was 12 TPI, LH also. I called Jet to find out whether they had a handwheel to fit, and the answer was no. The guy in Customer Service also said he had no idea why they used non-standard threads. I ended up using 13 pitch threads, and just ran it in until it jammed. It is possible that if you split a nut with hacksaw, you will get a thin nut that goes on kind of like a self-locking nut. It doesn't really need a lot of holding power. It just needs to press the One-way perforated disks against the sides of the wheel hard enough to prevent slipping.
Reply to
Leo Lichtman
Regarding 1/2" x 12 TPI it may be that they decided to use british whitworth thread which is 12 TPI. That may not be very common in the US but still readily available in the UK. If you could actually check the thread angle accurately and found it to be 55 degrees instead of 60 that would confirm it. I suspect that would be a lot of trouble though.
Jeff Dantzler wrote:
Reply to
David Billington
Thanks, guys.
I suspected something funny was afoot.
I'll go ahead and machine the flanges to get an extra 0.160".
The grinder is to be a dedicated tungsten grinder, so it will never see any appreciable loading. If I can get the wheels balanced, dressed, and attached, I'll be happy.
Reply to
Jeff Dantzler
Use a thinner wheel
Reply to
The design of the balancing flange / nut is such that the wheel thickness does not make a difference, since the grinder spindle nut bears on the ends of the flange.
If I used a thinner wheel, I could machine more off the flange.
Since I just spent good money on a pair of wheels, I'll start out by machining off what I can and that should get me where I need to be.
Oneway says spindle must be at least 1 7/8". Mine are 1 3/4", but I can gain 0.160" easily, which should work.
Reply to
Jeff Dantzler

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