... 3. CNC and automatic lathes There are many types chain roller,1. S small type2. P large type3. R large type4 ... . F flanged type The roller's metrial can be as per customer's request ... ,1. carbon steel, such as C45, C20 etc.2. ... plastic, such as PA6, etc. The roller also has many types heat treatment,1. quenched2. surface heat3. high-fre quency ...