DIN 125 200HV zinc nickel black Flat washer

A flat washer is a fastener that looks like a flat disk with a smooth cylindrical hole in the middle, the diameter of which is slightly larger than the diameter of the metric product with which it is used. It is made of steel with a hardness of 140, 200, 300 HV.

DIN 125 is used to increase the clamping area for various types of connections, reduce pressure on the surface of the connecting materials, and reduce friction between the nut and the surface of the part when tightening. In some cases, it is also used as a spacer to increase the distance between the nut and the surface of the part (this may be necessary if the thread of the bolt or screw is damaged at the clamping point).

Material of manufacture high-strength structural alloy steel. 

Coating: Zinc-nickel black. Zinc-nickel coating is an innovative anti-corrosion solution for fasteners that combines high protective ability, mechanical strength and environmental safety.

The key advantages of zinc-nickel coating are:

• Excellent corrosion resistance - more than three times higher than that of ordinary zinc;
• Low risk of hydrogen embrittlement;
• Compatibility with aluminum - does not form galvanic couples and does not cause corrosion in combination with aluminum parts;
• Increased heat resistance - retains its protective properties at changing temperatures and during prolonged operation in high-temperature conditions;
• Mechanical strength - harder than pure zinc, has better resistance to scratches and wear;
• Environmental friendliness - less formation of oxidation products, which means lower zinc emissions into the environment throughout the product's life cycle.
• Aesthetics and invisibility - the coating has a deep black color, which makes it hardly noticeable.

Analogs of GOST 11371-78, ISO 7089.