A.Fm B.Rm C.Rel D.As
A.45HRC B.40HRC C.45HRD D.40HRD
A.局部厚度不小于40µm,平均厚度不小于50µm B.局部厚度不小于45µm,平均厚度不小于50µm C.局部厚度不小于40µm,平均厚度不小于55µm D.局部厚度不小于45µm,平均厚度不小于55µm