Standard: GB /T 70.3 - 2008
Available sizes: M3 to M8 (5 sizes)
| Standard Body | Standard Number |
|---|---|
| GB | GB /T 70.3 |
| DIN | DIN EN ISO 10642 |
| ISO | ISO 10642 |
| UNI | UNI 5933 |
| Size | P | e | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|---|
| M3 | 0.7 |
| 1.5 |
| 2.52 |
| 3.82 |
| 2.873 |
| 8.96 |
| 7.53 |
| 2.5 |
| 2.58 |
| 4 |
| 2.48 |
| M4 | 1 | 2.2 | 4.020 | 5.82 | 4.583 | 13.44 | 11.34 | 4 | 4.095 | 6 | 3.72 |
| M5 | 1.5 | 3.6 | 6.020 | 9.78 | 6.863 | 22.40 | 19.22 | 6 | 6.140 | 10 | 6.2 |
| M6 | 2 | 4.5 | 10.025 | 13.73 | 11.429 | 30.8 | 26.52 | 10 | 10.175 | 14 | 8.4 |
| M8 | 2.5 | 5.6 | 12.032 | 19.67 | 13.716 | 40.32 | 36.05 | 12 | 12.212 | 20 | 10.16 |
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.