Lock nut introduction and nut classificatio

The working principle of the nut is that the friction between the nut and the bolt is used for self-locking, but the reliability of this self-locking will be reduced under dynamic load. In some important occasions, we will take some

anti-loosening measures to ensure Reliability of nut locking. The use of a lock nut is one of the anti-loosening measures. The manufacturing process of the fastener lock nut is: material modification cold head, Chamfering and center

hole-drilling and deburring, tapping, dephosphorization, heat treatment, grinding, thread, diameter rolling thread on the threaded hole-(pickling) oxidation treatment-defect detection, demagnetization-(pickling) oxidation Handling-

coating, inspection, packaging library. Nut material: carbon steel, stainless steel, copper, alloy, etc.

Nut types:

Stainless steel nuts
Lock nut，Hex nuts (GB6170/DIN934), thin nuts (GB6172/DIN439), heavy nuts (metric, American), nylon lock nuts (DIN985-DIN982 thick type), all metal lock nuts (DIN980M), cap nuts (DIN1587) ), flange nut (GB6177/DIN6923), flange nut nylon lock nut(DIN6926), four-corner welding nut(DIN928), hexagonal welding nut (DIN929), butterfly cap (GB62, DIN315, American), K cap, etc. Specification: M1.6-M64

Alloy steel nuts
Hexagon nuts (GB6170/DIN934, GB6175), flange nuts (GB6177/DIN6923)
Round nuts (GB812), small round nuts (GB810), American square nuts, American hexagonal nuts (ANSI/ASME B18.2.2), heavy nuts (metric, American). Specification: 5/16-4″.

Types of lock nuts:

The first is to use two identical nuts to screw on the same bolt, and add a tightening torque between the two nuts to make the bolt connection reliable.
The second is a special lock nut, which needs to be used together with a lock washer. The special lock nut is not a hexagonal nut, but a middle round nut. There are 3, 4, 6 or 8 gaps on the circumference of the nut (depending on the sizeof the nut and the product series of the manufacturer). Several notches are not only the focus of the tightening tool, but also the entry point of the locking washer.
The third type is to drill through threaded holes from the outer surface of the nut to the inner thread surface (usually two, distributed at 90 on the outer surface), used to screw in small diameter countersunk screws, the purpose is tothread Apply a centripetal force to prevent the lock nut from loosening.

A lock nut with better quality sold on the market is inlaid with a small piece of copper that is consistent with the thread of the lock nut on the inner surface ofthe nut to prevent the radial jack screw from directly contacting the locked thread and damaging the latter . This kind of lock nut has gradually begun to be applied in the occasion of the shaft end locking of rotating parts, such as theanti-loosening of the bearing at the mounting end of the ball screw.
The second anti-loose method is more reliable than the first, but the structure is relatively complicated. Compared with the first two, the third clock has the characteristics of better anti-loose effect, simpler and more beautifulstructure, and smaller axial size.