Standard: GB /T 31.3 - 2025
Available sizes: (M14) to M8 (7 sizes)
| Size | P | s_max | s_min | k_nominal |
|---|---|---|---|---|
| (M14) | 2 | 1.5 | 5.00 | 5.30 |
| (M18) | 3 | / | 6.30 | 6.66 |
| M10 | 1.5 | / | 3.20 | 3.50 |
| M12 | 2 | 1.5 | 4.00 | 4.30 |
| M16 | 2 | / | 5.00 | 5.30 |
| M20 |
| 3 |
| / |
| 8.00 |
| 8.36 |
| M8 | 1.25 | 1 | 2.50 | 2.75 |
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.