1. Advantages of cold heading:

It can produce bolts with higher density, higher hardness and stronger strength.

It can eliminate the axial tensile and extrusion stresses caused by knurling and increase the fatigue life of bolts.

The process is simple and the cost is low, which is suitable for the production of large quantities of products.

2. Disadvantages of cold heading:

It is easy to produce defects such as surface cracks and internal bubbles.

It needs to go through multiple surface treatments, such as pickling and heat treatment, to ensure the surface finish and oxidation resistance of the product.

3. Advantages of hot heading:

It can eliminate the residual stress of the material and improve the fatigue resistance of the bolt.

It can obtain materials with certain performance changes from the center to the surface, making the bolt performance more stable.

4. Disadvantages of hot heading

The process is complex and the manufacturing cost is high.

The heating and cooling process will cause defects such as deformation and discoloration of the material.