Standard: QC /T 381 - 2013
Available sizes: NPT1/4 to NPT3/8 (3 sizes)
| Size | P | k_max | k_min | s_max | s_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|
| NPT1/4 | 24 | 20 | 12 | 23.67 | 26.75 | 14 | 11 |
| NPT1/8 | 16 | 16 | — | 15.73 | 17.77 | 11 | — |
| NPT3/8 | 34 | 27 | 16 | 33.38 | 37.72 | 19 | 20 |
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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