ASTM A574:17 pdf download.Standard Specification for Alloy Steel Socket-Head Cap Screws.
5. Materials and Manufacture
5.1 The screws shall be fabricated from alloy steel made to a tine grain practice. In the event of controversy over grain size, referee tests on finished screws conducted in accordance with Test Methods El 12 shall prevail.
5.2 Screws in sizes through 0.750 in. diameter, and with lengths through ten times the nominal product size or 6.0 inches, whichever is shorter, shall be cold headed, except that when specified by the purchaser the screws shall be hot headed. Larger sizes and longer lengths shall be cold or hot headed at the option of the manufacturer, unless otherwise specified by the purchaser. Screws larger than 1.500 in. nominal diameter shall be permitted to be machined. Sockets shall be forged or machined at the option of the manufacturer.
5.3 Screws in sizes through 0.625 in. diameter, and for product lengths through 4 in. shall be roll threaded, unless otherwise specified by the purchaser. Larger products shall be rolled, cut, or ground at the option of the manufacturer.
5.4 Screws shall he heat treated by quenching in oil from above the transformation temperature and then tempered by reheating to at least 700°F to achieve the mechanical properties specified in Section 7 and Table I.
5.4.1 When specified by the purchaser, the minimum ternpering temperature shall he verified by subjecting screws to 680°F for 30 minutes at temperature. The mean cross section hardness of three readings on the screw before and after retempering shall not differ by more than 2 points hardness Rockwell C (HRC).
5.6.1 When a protective finish other than as specified in 5.5is required, it shall be specified on the purchase order with theapplicable finish specification.
5.6.2 When protective or decorative coatings are applied tothe screws， precautions specified by the coating requirementsto minimize internal hydrogen embrittlement shall be exer-cised.Additional precautions such as the requirements in TestMethod F1940 and Test Methods F606/F606M shall be byagreement with the purchaser.
6.Chemical Composition
6.1 The screws shall be alloy steel conforming to thechemical composition specified in Table 2 and the require-ments in Specification F2282.See Supplementary RequirementS1 when additional alloy steel grades are required.
6.2 One or more of the following alloying elements:chromium, nickel, molybdenum, or vanadium shall be presentin sufficient quantity to ensure that the specified strengthproperties are met after oil quenching and tempering. As a
guide for selecting material, an alloy steel should be capable ofmeeting the specified mechanical requirements if the“as oilquenched”core hardness one diameter from the point is equal
to or exceeds 25 HRC+ (55 × carbon content).
6.3 When product analyses are made by the purchaser fromfinished screws representing each lot，the chemicalcomposition,thus determined,shall conform to the require-ments prescribed for product analysis in Table 2.
6.4 Steel to which bismuth, selenium, tellurium, or lead hasbeen intentionally added shall not be permitted.
6.5 Chemical analyses shall be performed in accordancewith Test Methods,Practices, and Terminology A751.
ASTM A574:17 pdf download
