Standard: GB /T 819.2 - 2016
Available sizes: (M3.5) to M4 (5 sizes)
| Standard Body | Standard Number |
|---|---|
| GB | GB /T 819.2 |
| NF | NF E 25-119-2 |
| DIN | DIN EN ISO 7046-2 |
| ISO | ISO 7046-2 |
| Size | P | e | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|---|
| (M3.5) |
| 1.25 |
| 8.8 |
| 8.7 |
| 4.65 |
| 2 |
| 17.3 |
| 15.80 |
| 4 |
| 8.9 |
| 15.4 |
| 3.2 |
| M2 | 0.45 | 2.8 | 2.7 | 1.5 | 0.6 | 5.5 | 4.7 | 1 | 2.9 | 4.4 | 1.1 |
| M2.5 | 0.6 | 4.1 | 4.1 | 2.35 | 0.9 | 8.2 | 7.30 | 2 | 4.4 | 6.9 | 1.5 |
| M3 | 0.8 | 4.9 | 4.8 | 2.7 | 1.3 | 10.4 | 9.30 | 2 | 5.2 | 8.9 | 2 |
| M4 | 1.5 | 9.8 | 9.6 | 5 | 2.5 | 20 | 18.30 | 4 | 10 | 17.8 | 3.8 |
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.