5/8-11 X 4 1/2 HEX CAP SCREW GRADE 2 YELLOW ZINC

A hex cap screw, also known simply as a hex bolt, is a type of threaded fastener designed to be used with a threaded nut or tapped hole.

The "hex" in the name refers to the head of the screw, which has a six-sided (hexagonal) shape. This shape is designed to be turned with a wrench or a socket, providing a means to tighten or loosen the screw. The "cap" in the name generally indicates that the head of the screw is larger and flatter, offering a larger surface area to distribute the load or pressure applied during tightening.

Hex cap screws come in a variety of sizes, materials and thread pitches to suit different applications. They are commonly used in machinery, construction, automotive and other industries where strong and secure fastening is required.