Standard: BS 1769 - 1951
Available sizes: 1 to 7/8 (5 sizes)
| Size | P | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 6 | 2.74 | 1.536 | 12 | 2.3750 | 1.505 | 1.433 | 2.3300 | 1.464 |
| 1/2 | 11 | 1.23 | 0.647 | 18 | 1.0625 | 0.631 | 0.587 | 1.0375 | 0.603 |
| 3/4 |
| 7 |
| 2.09 |
| 1.155 |
| 12 |
| 1.8125 |
| 1.139 |
| 1.079 |
| 1.7825 |
| 1.095 |
| 5/8 | 9 | 1.66 | 0.901 | 14 | 1.4375 | 0.885 | 0.833 | 1.4075 | 0.849 |
| 7/8 | 6 | 2.53 | 1.409 | 12 | 2.1875 | 1.378 | 1.310 | 2.1425 | 1.341 |
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.