Pressing Pressure Control Standard for Self-Clinching Fasteners Pressure Selection & Defect Solutions

Pressing Pressure Control Standard for Self-Clinching Fasteners Pressure Selection & Defect Solutions

Pressing pressure is a key parameter in sheet metal clinching. Improper pressure will cause loosening, cracking and surface defects. This article provides reference pressure values and improvement solutions for common problems.

Basic Selection Rules

Required pressure increases with fastener size, sheet thickness and material hardness. Stainless steel needs higher pressure than cold-rolled steel and aluminum. Hydraulic machines suit large-size and thick plates, while pneumatic machines are for miniature and thin parts.

Reference Pressure Range

For standard S-series clinch nuts: M3 8~16 kN, M4 15~25 kN, M5 22~35 kN. Pressure for clinch studs shall be increased by 10%~15%.

Defects Caused by Abnormal Pressure & Solutions

Insufficient pressure leads to loosening and poor push-out force, increase pressure and check hole size. Excessive pressure causes dent, bulge and sheet cracking, reduce pressure and adjust stroke. Unstable pressure results in irregular defects, install pressure stabilizer and replace worn molds.

Standard Commissioning Process

Carry out trial pressing and first article inspection before mass production. Conduct regular sampling test during production. Re-confirm first article after changing product or sheet material.

Daily Maintenance

Check seals and pipelines regularly to prevent pressure leakage. Keep molds clean. Run machine idle to stabilize pressure after long-time shutdown.