Chrome Plated High Strength DIN931 Weld Bolts External Hexagonal Grade 8.8

8.8 grade external hexagonal chrome-plated high-strength weld bolt.

Description

8.8 high strength is the tensile strength ≥800Mpa, the yield strength ratio is 0.8, and the yield strength is ≥640Mpa.

8.8 high-strength welding bolts are durable and not easily damaged.

Chrome plating refers to the act of plating chromium as a plating layer on other metals.
Chromium is a kind of silvery white metal with a bluish tint. Metal chromium is easily passivated in the air, and a very thin passivation film is formed on the surface, thus showing the properties of precious metals.

The chromium-plated layer has a very high hardness, and its hardness can vary in a wide range of 400-1200HV according to the composition of the plating solution and process conditions. The chrome-plated layer has good heat resistance. When heated below 500℃, there is no obvious change in gloss and hardness. The temperature will start to oxidize and change color when the temperature is above 500℃, and the hardness will decrease when the temperature is above 700℃. The friction coefficient of the chrome layer is small, especially the dry friction coefficient, which is the lowest among all metals. Therefore, the chrome-plated layer has good wear resistance.

The chromium plating layer has good chemical stability. It has no effect in alkali, sulfide, nitric acid and most organic acids, but it can be dissolved in hydrochloric acid (such as hydrochloric acid) and hot sulfuric acid.

Cold heading equipment

Plating line

Test equipments

Go no go gauge