Hex head cap screws are used to secure an object within or against another object. They have tighter tolerances, has a chamfered end and a washer face under the bolt head. The main difference between a hex cap screw and hex bolt is a hex bolt does not have a washer face under the bolt head. Bare finish fasteners have very low corrosion resistance. This is a good choice for indoor use or when protection from the elements is not an issue. Grade 5 made from medium carbon steel. Quenched and tempered for higher tensile strength and holding power. Three radial bars head marking. Tensile strength: up to 1" - 120,000 p.s.i. (min), 1-1/8" dia. And up - 105,000 p.s.i. (min).