[Collins] Source for PEM nuts for trim ring

[Dr. Gerald N. Johnson]

On Tue, 2007-08-21 at 07:16 -0500, Brian K Harris wrote:
> 
> I'm working on a 30L1 that is missing the two self-clinching (PEM?) nuts in
> the top of the trim ring.  At least I think that's what was originally
> used.  New ones would be nice but two that can be removed from a non-usable
> trim ring will certainly work.  Does anyone have some for sale?
> 
> Brian K. Harris, WA5UEK

There are several styles of PEM nuts, not just made by Pennsylvania.
Each has a different pattern but all work on squeezing some metal into a
groove on the nut shank. When they break out, they usually take that
metal with them so the replacements, even of the same make, do not find
the metal to anchor them. Replacements may only hold with an epoxy. And
they often take a different size of hole. One that takes a larger hole
for the same thread size might be mounted with a press after drilling
the hole larger. I use a Whitney #5 Jr hole punch to set them.

McMaster-Carr sells such clinching nuts but won't tell who made them.
They have two styles in my catalog. www.mcmaster.com search for "captive
nuts."
-- 
73, Jerry, K0CQ, Technical Advisor to the CRA
All content copyright Dr. Gerald N. Johnson, electrical engineer