Special threads- Determining what it is.

I have a NSK ball screw I got off Ebay. It is great but I am trying to determine the thread of the lock nut on the end that tightens up on the thrust bearing. The bearing ID is 16mm. The lock nut threads are odd. THe OD is .581" and fits my 32 pitch thread gauge nicely. My problem is I cant find a tap to make a nut for it. I dont have thread wires to measure the pitch dia.
I have tried to look up the numbers onthe ball nut to see if NSK might have something listed but no luck. I cant even find the series this ball screw is.

I would appreciate any help in trying to figure out what it is.

Thanks
Scott

I would expect that the NSK ball screw is all metric. Furthermore, I would expect that they would use a standard precision locknut on the ends. I would check with you local bearing supply house, or whittet-higgins as they used to have a greta book outlining pretty much all available lock nuts.

Whittet-Higgins still have their info on the internet. You can down-load it in pdf form.

Dick Z

Whittet-Higgins is a very interesting website. I came across a .586-32 thread nut which looks like it would be the one to fit from my .581 OD measured dim and it fitting my 32 pitch thread gauge perfectly. I looked on the metric side and found a M15 X 1,0 which is .590 OD but .0398 pitch, Close to the .03125" pitch on a 32 thread. The thought that if it is a metric bearing size good chances are it is a metric thread is probably correct. I am going to get a metric thread pitch gauge and see how well a 1,0 pitch lines up.
Thanks for all the great help and web site direction.

Scott

M15 x 0.75 could be a 'standard' but unusual size. M15 x 0.8 might be bang in, if it exists.

See if this helps:
http://www.nskamericas.com/cps/rde/x...ccessories.pdf

I got the whittet higgins .586-32 ball screw nut and it fit perfectly. With shipping I got it from a local distributer for $7.50. Life is good again.
Scott

Sorry I didn't see this earlier. Thats a standard bearing locknut thread. Check here:

McMaster-Carr

Matt

NSK make both metric and imperial leadscrews. (Just thought I would add that)