Standard: ANSI B 18.5
Available sizes: 1/2 to 7/16 (7 sizes)
| Size | P | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 1.149 | 0.173 | 0.604 | 0.525 | 1.098 | 2.104 | 0.178 | 0.257 | 2.037 | 0.196 |
| 1/4 | 0.324 | 0.057 | 0.189 | 0.164 | 0.298 | 0.618 | 0.072 | 0.086 | 0.598 |
| 0.084 |
| 3/4 | 1.531 | 0.244 | 0.805 | 0.698 | 1.47 | 2.804 | 0.24 | 0.36 | 2.715 | 0.258 |
| 3/8 | 0.642 | 0.091 | 0.336 | 0.292 | 0.605 | 1.169 | 0.116 | 0.137 | 1.132 | 0.133 |
| 5/16 | 0.452 | 0.068 | 0.226 | 0.196 | 0.421 | 0.803 | 0.081 | 0.103 | 0.778 | 0.094 |
| 5/8 | 1.404 | 0.22 | 0.738 | 0.641 | 1.345 | 2.571 | 0.208 | 0.326 | 2.489 | 0.226 |
| 7/16 | 0.895 | 0.138 | 0.47 | 0.408 | 0.852 | 1.637 | 0.147 | 0.206 | 1.584 | 0.167 |
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.