Standard: ANSI B 18.3
Available sizes: 2# to 6# (5 sizes)
| Standard Body | Standard Number |
|---|---|
| GB | GB /T 2671.2 |
| DIN | DIN EN ISO 14579 |
| ISO | ISO 14579 |
| Size | P | e | r | k_max | k_min | s_max | s_min | ds_max | ds_min | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|
| 2# | 0.099 | 0.094 | 0.095 | 0.099 | 0.0949 | 48 | 56 | 0.154 | 0.099 | 0.161 |
| 3# | 0.125 | 0.111 | 0.121 | 0.125 | 0.1202 | 40 | 44 | 0.198 | 0.125 | 0.205 |
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.
| 4# | 0.164 | 0.178 | 0.159 | 0.164 | 0.1585 | 32 | 36 | 0.257 | 0.164 | 0.27 |
| 5# | 0.216 | 0.2 | 0.21 | 0.216 | 0.2095 | 24 | 28 | 0.314 | 0.216 | 0.324 |
| 6# | 0.25 | 0.221 | 0.244 | 0.25 | 0.2435 | 20 | 28 | 0.354 | 0.25 | 0.375 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.