Standard: QJ 2581 - 1993
Available sizes: M3 to M6 (4 sizes)
| Size | P | k_max | k_min | s_max | s_min | k_nominal |
|---|---|---|---|---|---|---|
| M3 | 7.66 | 7 | 6.78 | 2.8 | 2.92 | 2.68 |
| M4 | 11.05 | 10 | 9.78 | 4 | 4.15 | 3.85 |
| M5 | 17.77 | 16 | 15.73 | 6.4 | 6.58 | 6.22 |
| M6 | 20.03 | 18 | 17.73 |
| 7.5 |
| 7.68 |
| 7.32 |
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.
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