Clinching Fastener & Sheet Metal Hardness Matching Specification, Material Adaptation Guide For Clinch Cracking, Inadequate Engagement & Falling Off

Clinching Fastener & Sheet Metal Hardness Matching Specification, Material Adaptation Guide For Clinch Cracking, Inadequate Engagement & Falling Off

p>Clinching relies on tooth extrusion and metal deformation for permanent fastening. Many sheet metal factories only select parts by size without considering hardness and material matching. Soft sheets with hard clinch parts cause cracking, while hard sheets with soft clinch parts lead to slipping and insufficient engagement, forming mass production defects.

1. Hardness & Clinch Part Matching Table For Mainstream Sheet Metals

Sheet Material	Hardness Range	Matched Clinch Material	Forbidden Material	Molding Effect
SPCC Cold Rolled Steel	HRB 60~80	Carbon Steel S Series	High-hardness Stainless Steel	Optimal hardness matching with full engagement
5052/6061 Aluminum Alloy	HRB 40~60 (Soft)	CLA Aluminum Series	Carbon & Stainless Steel	Hard parts tear aluminum hole and cause collapse
SUS304 Stainless Steel	HRB 85~95 (Hard)	CLS Stainless Series	Ordinary Carbon Steel	Insufficient carbon steel hardness leads to slipping failure
Galvanized Steel Sheet	HRB 70~85	Galvanized Carbon Steel	High-hardness Stainless Steel	Excessive hardness difference causes dent and coating damage

2. Material Mismatch Causes For Four Clinching Failures

1. Carbon steel clinch parts on aluminum sheets: Hard steel tears aluminum texture and causes hole collapse and falling off; 2. Carbon steel parts on stainless sheets: Insufficient hardness leads to poor embedding and torque slipping; 3. Soft clinch parts on hard steel sheets: Deformed clinch teeth cause mass slipping and loosening; 4. Mixed material installation: Inconsistent deformation coefficients accelerate loosening and cracking under temperature alternation.

3. Standard Mass Production Material Matching Process

1. Confirm sheet material and hardness before production and select exclusive clinch series; 2. Conduct first article pull & torque test after sheet replacement before mass production; 3. Store different material clinch parts separately with clear labels to avoid wrong loading; 4. Fine-tune pressing force for hard sheets to ensure full tooth embedding and reliable fastening.