Metallics JSS3812 Screw 3/8-16 x 1/2 SKT S-Scr Cup St- (Jar 100)

The JSS3812 is a 3/8-16 x 1/2 inch socket set screw. 3/8-16 is the standard coarse (UNC) thread for a 3/8 inch diameter fastener, so it threads into any tapped 3/8-16 hole, and the 1/2 inch length is the overall screw length. Cup point, steel.

Cup point, which is what the JSS3812 has, is the general purpose choice: the hollowed ring bites into the mating surface and resists loosening under vibration, which is why it is the common point style for securing collars, pulleys, and conductors in a tapped lug. It does mar the part it clamps. If you need to clamp against a hardened or finished surface you plan to reuse without damage, or against a flat milled pad, a flat point is the better pick. For a drilled or spotted seat, a cone or oval point locates better.

It is a socket (SKT) set screw, so it drives with a hex key, not a screwdriver. The hex socket is internal and the screw body is headless, so it seats flush or below the surface of the part it is threaded into. Have a standard inch Allen key set on hand for a 3/8-16 socket set screw.

Steel. The JSS3812 is a plain steel cup point socket set screw, so for wet, outdoor, or corrosive locations you will want a stainless or coated set screw instead. In dry interior electrical and MRO work, plain steel is the normal spec.

100 pieces per jar. Metallics packs the JSS3812 in a jar rather than a box, which is the format most electricians and maintenance shops want on the truck for loose small fasteners.