The most common cap screw is the hex cap screw. This cap screw is a headed and externally threaded part designed for insertion through a close tolerance internally tapped hole and mated with a nut. Tension is induced by rotation of the cap screw head. There is often a washer forged under the head. The point at the threaded end of the cap screw is machined flat so it will fit into a drilled hole. Cap Screws usually have closer tolerances than do bolts.
The length of the threaded portion of the shaft on standard hex cap screws (all of our stock are standard items) is 2 times the diameter of the shaft plus 1/4 inch. So therefore short hex cap screws may be fully threaded or nearly fully threaded; long hex cap screws may have large portions of smooth unthreaded shaft above a shorter threaded section.
InStock Fasteners' hex cap screws may be standard hex head or flat hex head. Cap screw drive selection encompasses hex head unslotted or hex head slotted.