Standard: BS 1210 - 1963
Available sizes: 3# to 8# (6 sizes)
| Size | P | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|
| 3# | 0.108 | 1 | 0.205 | 0.081 | 0.113 | 0.104 | 0.114 | 22 | 0.215 | 0.073 |
| 4# | 0.136 | 2 | 0.256 | 0.100 | 0.141 | 0.131 | 0.154 | 18 | 0.267 | 0.090 |
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.
| 5# | 0.164 | 2 | 0.306 | 0.118 | 0.169 | 0.159 | 0.168 | 14 | 0.319 | 0.107 |
| 6# | 0.192 | 2 | 0.357 | 0.136 | 0.197 | 0.186 | 0.184 | 12 | 0.372 | 0.125 |
| 7# | 0.248 | 3 | 0.457 | 0.171 | 0.253 | 0.238 | 0.266 | 9 | 0.476 | 0.159 |
| 8# | 0.276 | 3 | 0.508 | 0.190 | 0.281 | 0.266 | 0.276 | 8 | 0.529 | 0.176 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.