Comma Scraper, Shanghai Donghui Roller specializes in making Comma Scraper which is high accuracy. And Shanghai Donghui Roller is the excellent expert all over the world. 1. Generally, the opening is along the symmetrical axis of the roller. 2.Material is excellent 45# seamless steel pipe or alloy steel 3. Precise process includes heat treatment, mechanical treatment, chromate treatment, grinding and so on. 4.The roller, straightness & out of roundness & proper alignment = 0.005mm 6.Hardness of surface >= HRC62 7.Finish of surface is Ra0.01um (14 levels) 8. Wearing resistance is excellet, friction effect is very clean. 9. used in coating machine, gumming machine, laminating machine, composite machine. Printing, packaging, leather, textile. Plastic, paper, and so on. DHG001 1*10 m.