Inside the six angle wrench, if required to black appearance, generally do what processing, wear and rust prevention effect will be better? How about the cost?
In addition, the plating black nickel or black chromium can also achieve your appearance and wear-resistant effect, but the cost is very high, I have not seen such products.
Market sales of black in the six angle wrench with alkali or blue black phosphating, from wear, and better, the cost is not high. But take note: after a bluing should do closed or rust, antirust performance is not good.
