1. Grade C gasket has no requirements for Ra3.2 and deburring.
2. Level C is applicable to medium assembly series, and level A is applicable to fine assembly series G B848-85 is mainly used for cheese head screws, and others are used for standard hexagon bolts, screws and nuts.
4. Mechanical property grade of material: steel 200HV; Austenitic stainless steel A200. 5. Marking example: standard series, nominal size d=8mm, performance grade 200HV, plain washer without surface treatment: washer GB97.1-85 8 200HV