Standard: GB /T 859 - 2025
Available sizes: 1.6 to 4 (5 sizes)
| Size | P | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|
| 1.6 | 2.1 | 1.25 | 0.58 | 0.8 | 2.35 | 0.5 | 0.9 | 1 | 0.42 | 0.7 |
| 2 | 3.1 | 1.5 | 0.68 | 1 | 3.4 | 0.6 | 1.1 | 1.2 | 0.52 | 0.9 |
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.
| 2.5 | 5.1 | 2.75 | 1.2 | 1.5 | 5.4 | 1.1 | 1.6 | 2.2 | 1 | 1.4 |
| 3 | 8.1 | 4 | 1.7 | 2.5 | 8.5 | 1.6 | 2.65 | 3.2 | 1.5 | 2.35 |
| 4 | 10.2 | 5 | 2.1 | 3 | 10.7 | 2 | 3.15 | 4 | 1.9 | 2.85 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.