Standard: GOST 3057 - 1990
Available sizes: 301 to 310 (10 sizes)
| Size | P | k_max | k_min | s_max | s_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|
| 301 | 28 | 1.8 | 0.3 | 12 | 1 | 0.8 | 0.0039 |
| 302 | 31.5 | 2.05 | 0.5 | 12.5 | 1.05 | 1 | 0.0054 |
| 303 | 20 | 1.5 | 0.3 | 9 | 1 | 0.5 | 0.002 |
| 304 | 50 | 2.85 | 0.5 |
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.
| 25.4 |
| 1.25 |
| 1.6 |
| 0.0143 |
| 305 | 25 | 1.8 | 0.3 | 14 | 1 | 0.8 | 0.0026 |
| 306 | 20 | 1.55 | 0.3 | 10.2 | 1.1 | 0.45 | 0.002 |
| 307 | 35.5 | 2.25 | 0.5 | 14 | 1.3 | 0.95 | 0.0085 |
| 308 | 25 | 1.8 | 0.3 | 10 | 1.3 | 0.5 | 0.0042 |
| 309 | 60 | 3.5 | 0.7 | 30 | 1.5 | 2 | 0.025 |
| 310 | 45 | 2.9 | 0.5 | 18 | 1.5 | 1.4 | 0.0157 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.