Metallics JSS1438 Screw 1/4-20 x 3/8 SKT S-Scr Cup St- (Jar 100)

Each jar holds 100 pieces. Metallics packs the JSS1438 in a jar rather than a box, which is what most electricians and maintenance shops want on the truck for a loose fastener used a few at a time.

A hex key. It is a socket drive set screw, so it is driven with an Allen wrench sized to the socket, not a flat or Phillips driver. There is no head on the screw, it seats flush or below the surface of the tapped hole.

The cup point on the JSS1438 is a hollow ring that bites into the mating shaft or bus, giving holding power on a shaft that does not have to be pre-dimpled. A flat point is the choice when you do not want to mar the part and need to reposition it, and a cone point is for a permanent set into a drilled detent. Cup point is the general purpose pick for locking a collar, lug, or grounding connection on a round conductor.

Steel. The JSS1438 is a plain steel 1/4-20 cup point socket set screw, which suits dry interior electrical work. For wet locations, exterior pedestals, or anywhere corrosion is a concern, specify a stainless 1/4-20 x 3/8 cup point instead.

It is the replacement screw for the tapped set screw holes you find across electrical gear: set screw connectors and lugs, ground clamps, strut and channel fittings, and conduit bodies that clamp on a conductor rather than thread onto it. Metallics catalogs the JSS1438 as an electrical fastener, and the jar of 100 is sized for a shop that loses or strips these regularly.