ISO 4032 Hexagon nuts are often used with bolts and screws. The results show that the self-locking ability and locking ability of the coarse hexagon nut are worse than that of the fine tooth hexagon nut, but the locking force is greater than that of the fine tooth hexagon nut; the fine tooth hexagon nut has good locking performance, which is suitable for anti vibration and easy to adjust the clearance, but the locking force is worse than that of the coarse hexagon nut, so it is suitable for the place where the clearance or torque should be adjusted. In general, coarse thread is used if there is no special requirement.

ISO 4032 hexagon nut is widely used, and it is often used with bolts, studs and screws to connect and fasten. Grade A (applicable to nominal thread diameter D ≤ 16 mm) and grade B (suitable for d > 16 mm) nuts are used in machines, equipment or structures with small surface roughness and high precision requirements. It is characterized by relatively large tightening force, which can be installed with a movable wrench, an open-ended wrench or a spectacle wrench, all of which require a larger operating space.

ISO 4032: However, with the advancement of science and the improvement of people’s awareness of quality, it is found that the provisions of this standard have brought great hidden dangers to quality and safety.

Because people always hope that in the process of matching bolts and nuts, if there is a quality accident, they always want the bolt to fail first, so that you can observe and prevent the accident. If the nut fails, the accident is sudden, so the EU and ISO International organizations have been revised, and a new standard, the ISO 4032 standard, has been produced.

The thickness of this standard has increased, so ISO898-2 was adopted as the testing standard. This mechanical performance standard stipulates that the proof loading capacity of the nut increases with the increase in specifications. For example, the level 8 nut gradually increases from 840MPa to 920MPa.