Summary Of Common Issues With Hex Socket Screw Heads

Hex socket screws (such as round head and pan head) are typically formed in one stroke through cold heading. Quality control of their heads is more complex than that of hex bolts, and the probability of issues occurring is relatively higher.

Common Problems and Cause Analysis:

1.Head Cracking

Material Cause: Excessive hardness of the material; annealing is required to reduce hardness.

Process Cause: Excessive mold opening and closing speed; equipment adjustment is needed to achieve a reasonable speed.

2.Eccentric Hex Socket

Mold Cause: Loose upper and lower punching modules, wear of the first punch, or roughness of the second ejector pin.

Solution: Inspect and adjust the mold assembly to ensure precise positioning.

3.Undersized Head (Non-Compliant)

Main Cause: Insufficient mold extrusion pressure or low speed.

Consequences: Uneven material cutting and non-standard head right angles.

Solution: Adjust the extrusion device and recalibrate the equipment stroke.

4.Other Related Issues:

Bent Shank: Usually caused by an oversized or worn die aperture; requires calibration, polishing, or replacement of the die.

Uneven Tail Cross-Section / Inconsistent Length: Primarily caused by non-straight material or rough die holes leading to positioning inaccuracies.

Conclusion and Recommendations

The key to ensuring screw quality lies in comprehensive control and coordination of raw materials, mold quality and debugging, and equipment performance, eliminating potential issues from both the source and the process.