Henan Shanjie Machinery Equipment Co.,Ltd.

Why is the pulley surface black?

Issuing time:2022-04-28 18:40

Before, a customer called the pulley and asked, "why is the surface of your pulley black?" The technician gave the answer. In short, this customer has been using the national standard pulley before, and its surface has not undergone any black treatment. With the development of industry, the European standard taper sleeve pulley has gradually entered the Chinese market, and has gradually replaced the national standard pulley due to its many advantages. The surface of the European standard pulley is treated with phosphating and blackening. Let's simply popularize what black treatment has.

General black surface treatment includes: blackening, black phosphating, black Dacromet, etc.

1. Blackened low-grade products for decorative domestic sales only have an oxide layer on the surface and have no rust prevention ability. They will rust in a few months and are not wear-resistant.

2. Black phosphating is used for export or products with high quality requirements. The film thickness is 3-5 microns, and the hemispherical film has the function of reducing wear and self lubrication. It has excellent rust prevention ability. It can resist the salt at sea when crossing the sea.

3. Dacromet process is applicable to products with low tolerance requirements and high anti-corrosion requirements. It is a zinc aluminum coating, similar to painting, but the cost is too high.


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