A Grade 8 Hex Head Cap Screw features medium carbon steel material and has undergone heat treatment. The two features result in a product with a high tensile strength than screws in lower classes such as 5.8, 4.8, and 4.6. The screw is fully threaded
The Grade 10.9 Hex head cap screw
is made from zinc-plated steel and features a coarse thread. The screw also has a portion of its shaft that is not threaded. The design of the screw head, which is six-sided, is made such that it fits a spanner torque wrench or a ratchet.
Both the Grade 10.9 and Grade 8 variants have varying finishes, but zinc is the most common. Besides, both cap screws feature the washer face beneath the head and chamfered point designs. As they have high tensile strengths, Grade 8 and 10.9 Hex Head Cap Screws are a common feature in the construction, mining, and automotive industries.