1) Standard: German standard, American standard, British standard, Japanese standard, etc., or non-standard items 
  
 2) Specification :2-64mm 
  
3) Material: spring steel (70 #, 65Mn), stainless steel, copper 
  
 4) Surface treatment: black, galvanized (blue, white, yellow), hot-dip galvanizing.
 
5) Packing: carton or gunny bags 25KG / unit or by the request of the customer
 
6) Other requirements: In accordance with the user's requirements