Standard: BS 1981 - 1991
Available sizes: (1#) to 8# (8 sizes)
| Size | P | k_max | k_min | s_max | s_min | ds_max | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|
| (1#) | 0.161 | 0.035 | 0.027 | 0.145 | 0.095 | 0.03 | 0.077 | 0.043 |
| (3#) | 0.27 | 0.054 | 0.045 | 0.25 | 0.156 | 0.54 | 0.133 | 0.071 |
| 0# | 0.118 | 0.026 | 0.019 | 0.104 | 0.071 |
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.
| 0.02 |
| 0.055 |
| 0.031 |
| 2# | 0.205 | 0.043 | 0.035 | 0.187 | 0.12 | 0.04 | 0.1 | 0.054 |
| 4# | 0.357 | 0.067 | 0.056 | 0.334 | 0.205 | 0.074 | 0.178 | 0.094 |
| 5# | 0.518 | 0.084 | 0.072 | 0.49 | 0.295 | 0.11 | 0.262 | 0.137 |
| 6# | 0.625 | 0.094 | 0.081 | 0.589 | 0.368 | 0.135 | 0.321 | 0.17 |
| 8# | 0.75 | 0.106 | 0.091 | 0.71 | 0.412 | 0.151 | 0.362 | 0.19 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.