ASTM A193 TECHNICAL DATA

ASTM A193 Grades and Markings

The ASTM A193 specification encompasses the standard that covers high-strength low-alloy steel shapes for bolting material used for pressure valves, flanges, vessels, and fittings for high-temperature applications.  For this specification, it covers wire, bars, bolts, studs, stud bolts, and screws. They are mainly used in chemical construction and petroleum applications. Although, this material is often utilized in national coarse thread pitches, but threads are specified 8 threads per inch (tpi) for diameters above 1 inch when being used in traditional applications.

ASTM A193 Mechanical Properties

ASTM A193 Specifications for Mechanical Properties governs the material specification defining mechanical properties, chemical composition, and preferential heat treatment. In addition, it governs product marking, hardness requirements, certifications, and more. ASTM A193 defines both SI (Metric) and inch-pound units.

A To meet the tensile requirements, the Brinell hardness shall be over 200 HBW (93 HRB).
B Class 1 is solution treated. Class 1A is solution treated in the finished condition for corrosion resistance; heat treatment is critical due to physical property requirement.
Class 2 is solution treated and strain hardened. Austenitic steels in the strain-hardened condition may not show uniform properties throughout the section particularly in sizes over 3⁄4 in. in diameter.
C For sizes 3⁄4 in. in diameter and smaller, a maximum hardness of 241 HBW (100 HRB) is permitted.
D For diameters 11⁄2 and over, center (core) properties may be lower than indicated by test reports which are based on values determined at 1⁄2 radius.

ASTM A193 Materials & Chemical Properties

Material and Chemical Property Requirements for the ASTM A193 governs minimum and maximum carbon, phosphorus, manganese, sulfur, silicon, chromium, nickel, and molybdenum percent content of steel fasteners within the ASTM A193 specification. The properties also include the minimum tempering temperature requirements. 

A Values are maximums unless a range or a minimum is indicated. Where ellipses appear in this table, there is no requirement and the element need not be determined or reported. The intentional addition of Bi, Se, Te, and Pb is not permitted.
B Product Analysis—Individual determinations sometimes vary from the specified limits as shown in the tables. The several determinations of any individual element in a heat may not vary both above and below the specified range. Product variation limits are over for maximums, over or under for ranges, and under for minimums, unless otherwise indicated.
C Typical steel compositions used for this grade include 4140, 4142, 4145, 4140H, 4142H, and 4145H. ^D For bar sizes over 31⁄2 in. [90 mm], inclusive, the carbon content may be 0.50 % max. For the B7M grade, a minimum carbon of 0.28 % is permitted, provided that the required tensile properties are met in the section sizes involved, the use of AISI 4130 or 4130H is allowed.
D For bar sizes over 31⁄2 in. [90 mm], inclusive, the carbon content may be 0.50 % max. For the B7M grade, a minimum carbon of 0.28 % is permitted, provided that the required tensile properties are met in the section sizes involved, the use of AISI 4130 or 4130H is allowed.
E Total of soluble and insoluble.