Does anyone out there have military or aerospace specs for stainless steel screws with nylon locking elements (plugs, patches, pellets, etc.)? These would be specs providing part numbers to buy them to.
These are usually called PEM[sup][®][/sup] nuts, etc. from the original name of the manufacturer, Penn Engineering & Manufacturing Corp. Their website mentions complete testing to NASM 25027, 45938, ASTM & PEM Fastener tests. Lots of product literature, CAD drawings, a technical library, etc. at
kenvlach-
You're preaching to the choir about clinch nuts. I asked about screws, not nuts. Also, it would be news to me if clinch nuts came with nylon locking elements! Could you provide a PEM part number, for instance?
No, I apologize – I saw StickScrew[sup]®[/sup] on their homepage and didn't investigate.
Can you use self-locking hex. socket screws, 18-8 SS with nylon patch
(-70° to +250° F), per ANSI/ASME B18.8?
Thread sizes 4-40 to ½-13, catalog page 2924
tunalover,
Just talking with my nut buddy and his comment was if you don't need a Mil-Spec fastener just ask for a Nyloc/Nylock/Nylok from an American manufacturer. This will insure a quality screw and save considerable coins. He has been seeing some poor quality imports in the Nyloc/Nylock/Nylok type screws.
Here is one he has been getting calls for. Look at the product specifications for all the standards
Thanks guys but my customers are pretty particular about the quality control that (supposedly) comes with MS, AN, or NAS hardware. I know that I can always go to a commercial mfgr. Also, AMSE B18.3 does not put forward a universally-recogized part numbering system.
Thanks MintJulep, but we are looking to buy these using an industry-standard part numbering system. We always have the option of creating a vendor item drawing. Note that IFI-524 is another spec for locking elements.
It gives the means that the company uses to number their screws.
I don’t believe there are any AN, MS or NAS screws with the inserts installed. This company takes screws and adds the inserts. I think it would be cheaper to use locking nuts or anchor nuts than those inserts.
MintJulep
Thanks for the links. MS15981 tells how to apply the locking element but it doesn't appear to put forth mil-standard part numbers. NAS1283 I could not find using the DLA's website for free specs (ASSIST Quicksearch).