Hex bolts, also called hexagon screw head bolts, hex cap bolts, hex-cap screws, or machine bolts, are a very common choice when it comes to construction and repair. Hexagon screw head bolts come in a large variety of sizes and diameters.

Increased Torque: The six-sided shape of the hex head allows for better grip and increased torque transfer during tightening or loosening. This makes hex head fasteners ideal for applications requiring higher levels of torque, such as automotive, machinery, and construction.

Hex cap screws must meet specific tolerances as described under ASME B18. 2.1-1996. The most common specifications for hex head cap screws include ASTM A449 & SAE J429: Grade 2, Grade 5 & Grade 8. Hex cap screws are commonly mistaken for hex bolts, but differ in many ways, including the way they are installed.

Hexagon head screws — also called hex screws, hex socket screws and hex head cap screws — have a six-sided head and preformed machine threads on the shank, or shaft. You might have seen hex screws abbreviated as HH or HX, depending on the manufacturer or retailer.