The first is the raw material, is not the national standard of stainless steel wire, different materials certainly not the same price, must have this certificate, to ensure that you buy qualified products.

The second is artificial or machine, this is not introduced, and certainly a lot of manual to be expensive;

The third amount is greater than the amount of less, the same open a machine, certainly less than the average number of higher;

The fourth is allowed to bias, the general aperture with the wire diameter will be a certain deviation, the deviation of the small, the deviation is cheap.

Qualification certificate