Standard: NF E 25
Available sizes: M2.5 to M4 (4 sizes)
| Standard Body | Standard Number |
|---|---|
| GB | GB /T 822 |
| DIN | DIN EN ISO 7048 |
| ISO | ISO 7048 |
| Size | P | k_max | k_min | s_max | s_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|
| M2.5 | 0.5 | 2.00 | 1.86 | 25 | 5.50 | 5.32 | 2 |
| M3 | 0.7 | 2.60 | 2.46 | 38 | 7.00 | 6.78 | 2 |
| M3.5 | 1 | 3.9 | 3.6 | 38 | 10.00 | 9.78 | 3 |
| M4 |
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.
| 1.25 |
| 5.0 |
| 4.7 |
| 38 |
| 13.00 |
| 12.73 |
| 3 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.