Red nylon is used for locknut inserts for applications up to 250F. For temperatures to 500F there are Vespel inserts. The wrenchable nuts are available as hex and double-hex styles in sizes from #10 through 13/4-in. diameters. Fixed and floating anchor or plate nuts come in sizes ranging from #4 through 5/8 in. diameters, depending on style. Barrel nuts range in size from #8 through 3/8-in. diameters and also have nonmetallic inserts.

SPS Technologies Aerospace Fasteners,
301 Highland Ave., Jenkintown, PA 19046,
(215) 572-3003,