1,tiny tolerance,high precision 2,Material: carbon steel 3,customized according to your demand 4,ISO9001 certificated Specifications:Material: bronzeSurface treatment: copper platedProcessing method: cold drawnRoughness: Ra 0.8-Ra3.21, we are a professional manufacture for various stamping punching parts. We can produce them according to your drawings or samples if possible.2, the material in our ...