5/16-18 BS 2470 Alloy Steel Hex Socket Head Cap Screw Grade 12.9

Description

5/16-18 BS 2470 hexagon socket cap head screw commonly used in machine parts, die fixturing, and clamping. The flat socket head enables driving where there is not sufficient space for wrenches or sockets and allows the screw head to sit flush on the surface. Ever Hardware provides custom-made fasteners and customizable packaging.

The hex socket screw drive has a hexagonal recess and may be driven by a hex wrench, also known as an Allen wrench, Allen key, hex key or inbus as well as by a hex screwdriver (also known as a hex driver) or bit. Tamper-resistant versions with a pin in the recess are available.
The German company Bauer & Schaurte patented the hex socket 1936 in Germany and offered products based on it to the market. The abbreviation “Inbus” is derived from “Innensechskant Bauer & Schurte”, analogous to the US use of “Allen key”.

Heat treating is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve the desired result such as hardening or softening of a material. Heat treatment techniques include annealing, case hardening, precipitation strengthening, tempering, normalizing and quenching. It is noteworthy that while the term heat treatment applies only to processes where the heating and cooling are done for the specific purpose of altering properties intentionally, heating and cooling often occur incidentally during other manufacturing processes such as hot forming or welding.

12.9-grade 5/16-18 BS 2470 means that a component manufactured form this grade of steel has 12X100 N/mm^2 tensile strength and 9 is a multiplier means 90% of 1200 = 1080 N/mm^2 is the yield strength of the grade.
Similarly, we also have grade 8.8, 10.9, 6.8 also. This is an imperial method implied by engineers to differentiate between different sets of steel grades. Mainly used to differentiate the bolts and nuts. like Grade 12.9 Hexagonal Bolt.