Full Thread Hex Bolt A320 L7 hex bolt alloy bolt
ASTM A320 Class L7 fasteners are manufactured using high strength materials ideal for the manufacture of fastener product bolts, studs and bolts that can be used in a wide range of high temperatures in bolting applications.
Grade L7 corresponds to chrome steels, while A320 grade L7m bolts correspond to those steels that mainly contain chromium and molybdenum as alloying agents. Often, the sole purpose of quenching and tempering A320 L7 studs is to develop certain desired mechanical properties. Specifically, the above heat treatment was performed on A320 L7 bolts to optimize their tensile strength properties. L7 bolts are 4 inches in diameter. Charpy impact testing is required for A320 L7 bolts larger than 1/2 inch in diameter.