What are the maintenance and material classification of ratchet wrenches?

Maintenance and maintenance
1. There must be no rust, burrs, cracks, spots, etc.;
2. The flip is symmetrical, and the laser lettering should be clear;
3. The torque must meet the specified standards, and the card position must be accurate
4. The operation of the ratchet wrench should be flexible, and the pin should not be loose
Ratchet wrench material classification
1. Bright chrome: bright like a mirror;
2. Chromite: dull;
3. Electrophoresis: black, bright, under the action of external direct current, the charged particles move towards the cathode or anode in the dispersed medium force to promote the separation of substances;
4. Phosphating: black, but with a dark gloss. When the substance is immersed in the phosphating solution, a layer of insoluble crystalline phosphorus is deposited on the surface of the toilet, which is the process of hydrochloric acid conversion.
5. Gray nickel: It is a brand-new surface treatment method, which has strong anti-rust ability and will increase the service life of the product.
6. There are other treatments such as blackening, pearl nickel and titanium plating.