Standard: ASME B 18.21
Available sizes: 2# to 8# (6 sizes)
| Size | P | k_max | k_min | s_max | s_min | k_nominal |
|---|---|---|---|---|---|---|
| 2# | 0.107 | 0.062 | 0.043 | 0.101 | 0.239 | 0.034 |
| 3# | 0.133 | 0.079 | 0.055 | 0.127 | 0.300 | 0.045 |
| 4# | 0.174 | 0.096 | 0.067 | 0.167 | 0.375 | 0.057 |
| 5# | 0.227 | 0.130 | 0.091 |
| 0.220 |
| 0.497 |
| 0.080 |
| 6# | 0.322 | 0.143 | 0.100 | 0.314 | 0.619 | 0.108 |
| 8# | 0.385 | 0.170 | 0.119 | 0.377 | 0.738 | 0.123 |
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.