Metallics JSS1434SS Screw 1/4-20 x 3/4 SKT S-Scr Cup 18- (Jar 100)

At 3/4 inch, the JSS1434SS has roughly three times the thread length of the 1/4 inch diameter, so in a thin-wall collar the tail can protrude past the far side of the tapped hole before it ever seats on the shaft. Use the 3/4 inch length where you need reach through a thick boss or across a gap. For a thin collar, step down to a shorter 1/4-20 set screw so the point lands on the shaft with the screw still inside the hole.

A cup point, which is what the JSS1434SS has, has a hollowed ring edge that digs slightly into the mating surface and resists backing out. That is the standard choice for locking a collar, pulley, or hub onto a shaft in permanent or semi-permanent service. If you need to clamp against a hardened or soft shaft without marring it, or you expect to reposition the part often, a flat point set screw is the better pick.

It is a socket (hex key) drive screw, not a slotted or Phillips head. A 1/8 inch hex key is the standard drive size for a 1/4-20 socket set screw. The screw body is headless, so it seats flush or below the surface of the collar it threads into.

The JSS1434SS is an 18-8 stainless screw, which is the common austenitic stainless grade for fasteners and gives good general corrosion resistance. That makes it suitable for damp interior, exterior, and washdown work where a plain carbon steel set screw would rust. For chloride-heavy or coastal exposure, a 316 stainless fastener holds up better than 18-8.

They ship 100 screws to a jar. The jar pack is how Metallics bundles small electrical fasteners for shop or truck stock, so you get a resealable container rather than loose bulk, which matters if you are keeping a bin of odd fasteners on a service van.