What Are ASTM A320 Grade L7 Bolts? For the production of bolts, studs, stud bolts, and other fasteners for bolting pressure vessels, valves, flanges, and fittings for various process industries across major industrial sectors in low-temperature applications, ASTM A320 L7 Bolts is a material specification for chromium-molybdenum steel. Chemically ASTM A320 Grade L7 equivalent...