Standard: JIS B 1255
Available sizes: (4.5) to 8 (5 sizes)
| Size | P | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|
| (4.5) | 6.7 | 0.8 | 0.85 | 6.4 | 17.5 | 9 | 12 | 17 | 0.75 |
| 4 | 5 | 0.6 | 0.64 | 4.8 | 15 | 8 | 12 | 14.5 | 0.56 |
| 5 | 10.9 | 1 | 1.055 | 10.5 | 26 |
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.
| 9 |
| 14 |
| 25.4 |
| 0.945 |
| 6 | 14.9 | 1.2 | 1.265 | 14.5 | 32 | 10 | 14 | 31.2 | 1.135 |
| 8 | 16.9 | 1.4 | 1.47 | 16.5 | 35 | 12 | 16 | 34.2 | 1.33 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.