A 320


Mechanical properties of fasteners made of carbon steel and alloy steel

Alloy-Steel and Stainless Steel Bolting for Low-TemperatureService1

The ASTM A320 specification covers alloy steel and stainless steel bolting materials for low temperature service. This standard covers rolled, forged, or strain hardened bars, bolts, screws, studs, and stud bolts used for pressure vessels, valves, flanges, and fittings. Like the ASTM A193 specification , unless otherwise specified, the 8UN thread series is specified on fastener larger than 1” in diameter. Below is a basic summary of a few of the common grades within the ASTM A320 specification. A number of other less common grades of ASTM A320 exist, but not covered in the description below.

ASTM A320 Grades
L7 Hex bolts, screws, stud bolts, double ended studs, Stud for foundation, wind energy bolts, Fasteners for wind turbines
L7M Hex bolts, screws, stud bolts, double ended studs, Stud for foundation, wind energy bolts, Fasteners for wind turbines
L43 Hex bolts, screws, stud bolts, double ended studs, Stud for foundation, wind energy bolts, Fasteners for wind turbines