Hexagon Nut Classification

Hex nuts are classified into three types according to the nominal thickness, type II and thin. Nuts of class 8 or higher are divided into two types, type I and type II.

The type I hex nut is the most widely used, and the type 1 nut is divided into three grades A, B, and C. The grade A and grade B nuts are suitable for machines, equipment, and structures with low surface roughness and high precision. Class C nuts are used on machines, equipment or structures where the surface is rough and the accuracy is not high;

Type II hex nuts are thicker and are often used where assembly and disassembly are often required.

The I-shaped nut refers to the ordinary hex nut with the nominal height of the nut m≥0.8D, and its type size should meet the requirements of GB/T6170;

The height of the type II nut is higher than that of the type 1 nut, and the size of the type should conform to GB/T6175. There are two purposes for adding a type II nut: one is to obtain a relatively inexpensive nut by increasing the height of the nut.

Because the 8-level I-shaped nut of D≤M16 does not need heat treatment, in the 8-level nut, only the type 2 nut is used for the specification of D>M16~39.

Obviously, the I-nut without heat treatment can not meet the mechanical performance requirements of the 9-stage nut. Another purpose of the Type II nut is to obtain a 12-stage nut with better toughness. As the height of the nut increases, the guaranteed stress index can be achieved at a lower quenching and tempering hardness, thus increasing the toughness of the nut.

According to the distance between the teeth: standard teeth, regular teeth, fine teeth, very fine teeth and anti-tooth.

Classified by material: stainless steel hex nut and carbon steel hex nut, copper hex nut, iron hex nut.

Classified by thickness: hexagonal thick nut and hexagonal thin nut.

Classified by usage: hot-melt copper nut, hot-pressed copper nut, embedded copper nut and ultrasonic copper nut.