Grade 8 Hex Cap Screw, Plated

Grade 8 Material Marking

Mechanical PropertiesGrade 8

Chemical PropertiesGrade 8

1. 1. For steels of these types there shall be sufficient hardenability to ensure a microsructure consisting of approximately 90% martensite (refer Table 3) in the core of threaded sections of the fasteners after hardening and quenching and before tempering.
2. 2. When boron is added the limits shall be 0.0005 % to 0.003 %.
3. 3. Alloy steel shall contain at least one of the following elements in the minimum quantity given: chromium 0.30 %, nickel 0.30 %, molybdenum 0.20 %, vanadium 0.10 %, manganese 1.65%. Where elements are specified in combinations of two, three, four, or five and have alloy contents less than those given above, the limit value to be applied for steel class determination is 70 % of the sum of the individual limit values shown above for the two, three, four or five elements concerned.
4. 4. For steels of these types there shall be sufficient hardenability to ensure a microsructure consisting of approximately 90% martensite (refer Table 3) in the core of threaded sections of the fasteners after hardening and quenching and before tempering.
5. 5. For studs only, sulfur content may be 0.13% maximum.
6. 6. Alloy steel used to make fasteners by hot forging or machining may have a maximum content by weight of 0.030% P (phosphorus) and 0.040% S (sulfur).

Dimensional SpecificationsGrade 8

1. All dimensions are in inches.
2. Usable thread length for Hex Head Cap Screws under 6 1/4" long can be approximated by the equation THREAD LENGTH = (2 X DIAMETER) + 1/4″