Socket Cap Screws are known as Hex Head Cap Screws or Hex Bolts. They are used to secure an object within or against another object. They have tighter tolerances, have a chamfered end and a washer face under the bolt head. Made from medium carbon steel. Length is measured from under head to end of bolt. Steel is zinc plated for moderate protection against rust. Use hot dipped galvanized finish or stainless steel where corrorsion and rust is of concern or for exterior projects. Best for areas where high strength is desired. Grade 5 is similar in strength to metric class 8.8. Ideal for indoor projects, construction, agricultural, and automotive applications. Use matching grade 5 nut.