Standard: GB /T 9074.31 - 2017
Available sizes: 2.5 to 5 (5 sizes)
| Size | P | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|
| 2.5 | 2.85 | 0.15 | 0.7 | 0.5 | 2.75 | 7 | 0.72 | M3 | 6.64 | 0.85 |
| 3 | 3.72 | 0.42 | 1.1 | 0.9 | 3.6 | 9 | 1.12 | M4 | 8.64 | 1.3 |
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.
| 3.5 | 5.62 | 1.53 | 1.7 | 1.3 | 5.5 | 14 | 2.3 | M6 | 13.57 | 2.6 |
| 4 | 9.45 | 6.82 | 2.7 | 2.3 | 9.3 | 23 | 3.3 | M10 | 22.48 | 3.6 |
| 5 | 11.18 | 13.3 | 3.3 | 2.7 | 11 | 29 | 3.8 | M12 | 28.48 | 4.1 |
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