Standard: QC /T 638 - 2000
Available sizes: 10 to 8 (6 sizes)
| Size | P | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|
| 10 | 16.2 | 22.365 | 22.035 | 16.335 | 16.065 | 2.2 | 1.8 | 22.2 | 2 |
| 12 | 20.2 | 27.365 | 27.035 | 20.365 | 20.035 | 2.2 | 1.8 | 27.2 | 2 |
| 14 | 24.2 | 33.395 | 33.005 | 24.365 | 24.035 |
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.
| 2.2 |
| 1.8 |
| 33.2 |
| 2 |
| 16 | 27.2 | 36.395 | 36.005 | 27.365 | 27.035 | 2.2 | 1.8 | 36.2 | 2 |
| 6 | 8.2 | 12.335 | 12.065 | 8.31 | 8.09 | 2.2 | 1.8 | 12.2 | 2 |
| 8 | 12.2 | 16.335 | 16.065 | 12.335 | 12.065 | 2.2 | 1.8 | 16.2 | 2 |
© 2026 Ningbo Ruixi Metal Surface Technology Co., Ltd.. All rights reserved.