Standard: QC /T 345 - 1999
Available sizes: 20 to 30 (7 sizes)
| Size | P | k_max | k_min | s_max | s_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|
| 20 | 20.5 | 0.9 | 2.5 | 20.65 | 20.35 | 1 | 3 |
| 22 | 23.2 | 0.9 | 2.5 | 23.35 | 23.05 | 1 | 3 |
| 24 | 25.9 | 1 | 3.2 | 26.05 | 25.75 | 1.1 | 3 |
| 25 |
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.
| 29.6 |
| 1 |
| 3.2 |
| 29.75 |
| 29.45 |
| 1.1 |
| 3 |
| 26 | 32.2 | 1 | 3.2 | 32.4 | 32 | 1.1 | 3 |
| 28 | 34.2 | 1 | 3.2 | 34.4 | 34 | 1.1 | 3 |
| 30 | 36.5 | 1 | 3.2 | 36.7 | 36.3 | 1.1 | 3 |
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