Paul C. Buff, Inc. Technical Forum

A small nut has come off on my PLM adapter ring. What size do I need to replace it?

They appear to be M4 x 0.70.

Just to clarify, these are the small nuts x 3 that are furthest from the mounting ring.

They would be the same size at each end of the three rods, so there are 6 nuts total, all the same size.

thanks!

So, i bought the M4 .7 nuts and they didn't fit. The thread pitch was wrong or something. I was able to get it fastened but I'm afraid it's never coming off again.

Are you 100% sure it was an M4 .7?

M4 .7 and 8-32 are very similar in size. At the time, I was unable to access any documentation that listed the size, specifically (it is not something we all need all the time), so we had to manually evaluate the threads. Since they are both so small, it was difficult to assess, but the threads did appear to be M4 .7.

However, your feedback prompted me reevaluate the the threads, and I was able to find documentation that they are indeed 8-32 threads rather than the M4 .7. I do apologize for this error.

If there has been damage done from this, please let us know, I am sure we can correct it for you.

I could tell I was re-forming the threads as I screwed it down. Is the little metal rod something that can be ordered as a replacement part?

It is not a part for sale, but call customer service, and we should be able to get you taken care of PDQ.