Standard: DIN 6903
Available sizes: ST2.9 to ST4.2 (4 sizes)
| Standard Body | Standard Number |
|---|---|
| GB | GB /T 97.5(L) |
| DIN | DIN EN ISO 10669(L) |
| ISO | ISO 10669(L) |
| Size | P | k_max | k_min | s_max | s_min | ds_max | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|
| ST2.9 | 3 | 1 | 1.06 | 3.1 | 11 | 0.69 | 10.73 |
| 0.94 |
| ST3.5 | 3.55 | 1 | 1.06 | 3.67 | 12 | 0.81 | 11.73 | 0.94 |
| ST3.9 | 4.7 | 1.6 | 1.68 | 4.82 | 15 | 2 | 14.73 | 1.52 |
| ST4.2 | 7.15 | 2 | 2.09 | 7.3 | 24 | 6.47 | 23.67 | 1.91 |
Standard corrosion protection for indoor and mild outdoor environments.
Salt spray: 96–200 hours | RoHS compliant (trivalent chromium)
High-performance coating for automotive, marine, and harsh environments.
Salt spray: 720–1500 hours | Recommended for grade 8.8+
Heavy-duty protection for structural and outdoor applications.
Salt spray: 500–1000 hours | Thread tolerance adjustment required
Note for high-strength fasteners (Grade 10.9, 12.9): Electroplating processes require hydrogen embrittlement relief baking (minimum 4 hours at 200°C within 4 hours of plating). Contact our engineering team for grade-specific plating recommendations.
Request detailed technical specifications, material certifications, and availability information for your application requirements. Our engineering team can provide product recommendations, custom specifications, and technical documentation.
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.