M5-0.8X40 Metric Socket Head Cap Screw Class 12.9 ISO 4762 Black Oxide (Pack Qty 100) BC-M5040CSP

High alloy metric socket cap screws are comparable, but not exactly equivalent to U.S. alloy steel socket cap screws. Ideal for precision assembly work with close tolerances and applications needing a well-tooled appearance. Supplies greater tensile strength than equivalent sizes of Class 8.8 or 10.9 hex head cap screws while requiring less surface area or conterbore since the fastener is internally wrenched High alloy metric socket cap screws shall be made from an alloy steel which conforms to the following chemical composition requirements-- Carbon: 0.20-0.50%; Phosphorous: 0.035% maximum; Sulfur: 0.035% maximum; and one or more of chromium, nickel, molybde