Hardened Machine Screws Hexagon Knurling Cap Grade 12.9 Black Bolt

The hardened machine screws are 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 with the surface. 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. Ever Hardware provides custom-made hardened machine screws and customizable packaging.

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.

Zinc coatings prevent oxidation of the protected metal by forming a barrier and by acting as a sacrificial anode if this barrier is damaged. Zinc oxide is a fine white dust that (in contrast to iron oxide) does not cause a breakdown of the substrate’s surface integrity as it is formed.

12.9-grade steel means that a component manufactured from 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.

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