Standard: ASME B 18.27
Available sizes: 1/4 to 7/32 (6 sizes)
| Size | P | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|
| 1/4 | NA5-56 | 0.042 | 0.044 | 0.430 | 0.434 | 0.870 | 1.588 | 0.426 | 0.040 |
| 1/8 | NA5-18 | 0.025 | 0.027 | 0.143 | 0.146 | 0.375 | 0.177 | 0.140 | 0.023 |
| 3/16 |
| NA5-37 |
| 0.035 |
| 0.037 |
| 0.292 |
| 0.296 |
| 0.660 |
| 0.680 |
| 0.288 |
| 0.033 |
| 3/32 | NA5-12 | 0.015 | 0.017 | 0.093 | 0.094 | 0.270 | 0.059 | 0.090 | 0.013 |
| 5/32 | NA5-25 | 0.025 | 0.027 | 0.204 | 0.207 | 0.516 | 0.322 | 0.201 | 0.023 |
| 7/32 | NA5-50 | 0.042 | 0.044 | 0.385 | 0.389 | 0.810 | 1.451 | 0.381 | 0.040 |
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.