Standard: BS 4174 - 1972
Available sizes: 2# to 8# (4 sizes)
| Size | P | e | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2# | 5.71 | 0.031 | 0.039 | 0.79 | 0.63 | 4.95 | 1.7 | 0.195 | 0.067 | 0.99 | 0.225 |
| 4# | 8.43 | 0.045 | 0.054 | 1.14 | 0.94 | 7.42 | 2.54 |
| 0.292 |
| 0.100 |
| 1.37 |
| 0.332 |
| 6# | 11.13 | 0.056 | 0.067 | 1.42 | 1.27 | 9.88 | 3.35 | 0.389 | 0.132 | 1.7 | 0.438 |
| 8# | 16.13 | 0.072 | 0.084 | 1.83 | 1.85 | 14.43 | 4.85 | 0.568 | 0.191 | 2.13 | 0.635 |
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.