GB/T 97.1-2002 in English

《GB/T 97.1-2002平垫圈 A级》由TC85（全国紧固件标准化技术委员会）归口，主管部门为中国机械工业联合会。

1 Range
This standard specifies the plain washer with nominal size (large diameter of thread) among 1.6-64 mm, standard series and hardness grade of 200 HV and 300 HV, and production grade of grade A.
The washer with hardness grade of 200 HV is applicable to:
- Hexagon bolt and screw nail with performance level to 8.8 and production grade of A and B;
- Hexagon bolt with performance level to 8 and production grade of A and B;
- Stainless steel and the hexagon bolt, screw nail and hexagon nut with similar chemical compositions;
- Face-hardened thread rolling screws
The washer with hardness grade of 300 HV is applicable to:
- Hexagon bolt and screw nail with performance level to 10.9 and production grade of A and B;
- Hexagon bolt with performance level to 10 and production grade of A and B;
Select from GB/T 5286 if demand the size out of those specified in this standard.
The user shall check the applicability of this type of washer when it is used for clamping the parts of the soft materials or the blowhole of the large bolt on workpiece.