Size: 1/4 inch-20 X 1-1/4 inch. Headless screw that sits flush or below the surface once installed. Internal socket drive requires Allen wrench (hex key) to install. Installs into an internally threaded hole to hold an object into place. Often used in machinery to secure gears to shafts. Thread Type: Coarse, Thread Class: UNC-3A, Point Style: Cup Point. Specification(s) Met: ASME B18.3 and ASME B1.1.
