1. Unqualified Material: Bad Material, Oil not Even or Chemical not Qualitified.

  2. Environmental: Stock in a humid Environment.

  3. No Oil: Bfore Punching, no Oil added on the material.

  4. Burrs: Burrs on the Surface, uncompletely plated.

  5. Rough Moulds: Rough Surface of Moulds break the surface of the products.