Material Selection and Performance Requirements for Cold Heading Process of Fasteners (Part I)

   FastenersCold heading is widely used in various industrial sectors such as aerospace and automobiles. It is mainly used for the processing technology of fasteners such as bolts, studs, screws, nuts, etc. It has the technical characteristics of smooth operation, high precision, high production speed, and easy automation. Then, Let's learn about the selection and performance requirements of cold heading processing materials for fasteners!

On the other hand, the multi-station automatic upsetting machine adopts the cold heading method, and the disc element or bar material is transported through the roller gear and transported in turn. One machine completes the cutting material, ball head stamping, corner stamping, punching and several processes. The cold heading machine is arranged horizontally and has the characteristics of accurate positioning, stable operation and convenient maintenance. Secondly, a brief introduction of cold heading process when processing fasteners.

Performance requirements for cold heading parts of 1. fasteners

1) The connection between the crankshaft and the body and the impact connecting rod is made of high wear-resistant alloy copper tile, which has large bearing capacity, long life and low maintenance cost.

2) The body is cast by ductile iron with alloy, which has high tensile strength and good wear resistance.

3) Adopting two-stage gear transmission system, high transmission efficiency and large transmission torque.

4) Equipped with pneumatic clutch brake to reduce the power consumption of the motor.

5) The cutting system adopts a guide plate to drive the cutter bar, the guide plate reciprocates, and the cutting force is transmitted in a straight line, with large and stable strength and good dynamic balance.

6) The clamp system can be turned over or moved in parallel, which is conducive to the arrangement of the molding process.

7) Equipped with frequency converter device, no speed regulation can be carried out within a certain range.

8) Equipped with fault detectors and safety protection devices, which will automatically stop when the equipment fails, and protect the equipment and molds as much as possible.

9) Install a thrust device on the feed box to improve the feeding accuracy.

10) The oil circuit design of the lubrication system is simple and efficient. On the basis of ensuring circulating filtration, it can effectively protect the punch and the workpiece.

Selection of Cold Heading Materials for 2. Fasteners

1) The raw material must be spheroidized and annealed, and the metallographic tissue of the material is spherical pearlite.

2) In order to reduce the cracking tendency of the material as much as possible, to increase the life of the mold, and to increase the plasticity, the cold drawn material is required to have the lowest possible hardness.

3) The dimensional accuracy of raw materials generally depends on the specific requirements and technical conditions of the product, while multi-station cold heading generally requires lower dimensional accuracy for shrinkage and strong shrinkage.

4) The surface quality of raw materials requires that the lubricating film be dull dark color, and the surface shall not have defects such as scratches, folds, cracks, napped, rust, oxide skin and indentation numbness.

5) The total thickness of the decarburized layer in the radial direction of the raw material is required to be less than 1% of the diameter of the raw material.

6) In order to ensure the cutting quality during cold forming, the raw material requires a hard surface and a soft heart.

7) Raw materials are subjected to cold heading test to increase deformation resistance through cold hardening. The lower the sensitivity of the material to cold hardening, the better.