Standard: GB /T 547
Available sizes: a1 to a7 (7 sizes)
| Size | P | k_max | k_min | s_max | s_min | ds_max | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|
| a1 | 57 | 19 | 16 | 25 | 4 | 0.63 | 40 | 72 |
| a2 | 78 | 26 | 22 | 34 | 5 | 1.43 | 50 | 98 |
| a3 | 98 | 34 | 28 | 42 | 7 | 3.2 | 68 | 130 |
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.
| a4 |
| 122 |
| 40 |
| 36 |
| 50 |
| 9 |
| 6 |
| 80 |
| 160 |
| a5 | 151 | 52 | 45 | 61 | 11 | 11.5 | 100 | 192 |
| a6 | 174 | 60 | 50 | 74 | 13 | 17.8 | 120 | 235 |
| a7 | 215 | 75 | 62 | 91 | 15 | 35 | 156 | 280 |
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