GB /T 819.1 (GB) and UNI 7688 (UNI) are equivalent fastener standards that specify the same or very similar products. Both standards cover 5 fastener types in our database.
GB /T 819.1 (GB standard) and UNI 7688 (UNI standard) are equivalent standards that define the same fastener geometry and mechanical requirements. Minor differences may exist in tolerances, marking requirements, or referenced test methods, but the products are interchangeable in most applications. Always verify specific project requirements with your engineer.
| Property | GB /T 819.1 | UNI 7688 |
|---|---|---|
| Standard Body | GB | UNI |
| Product Types | 5 fastener types | |
| Interchangeable? | Yes — equivalent standard | |
From: Countersunk Flat Head Screws (Common Head Style) with Cross Recess - Part 1: Property Class 4.8 — applies to both GB /T 819.1 and UNI 7688
| Size | P | e | r | k_max | k_min | s_max | s_min | ds_max | ds_min | k_nominal | ds_nominal |
|---|---|---|---|---|---|---|---|---|---|---|---|
| (M3.5) | 1.5 | 9.8 | 10 | 17.78 | 5 | 3 | 20 | 3.8 | 4 | 18.30 | 2.5 |
| M1.6 | 0.4 | 1.9 | 1.9 |
Both GB /T 819.1 and UNI 7688 fasteners are available with various surface treatments. Common options for these standards include:
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 |
| 1.2 |
| 0.8 |
| 4.4 |
| 1 |
| 0 |
| 3.8 |
| 0.5 |
| M2 | 0.5 | 3 | 3.2 | 5.2 | 1.65 | 1 | 6.3 | 1.25 | 1 | 5.5 | 0.8 |
| M2.5 | 0.7 | 4.4 | 4.6 | 8.04 | 2.7 | 1.4 | 9.4 | 1.75 | 2 | 8.40 | 1 |
| M3 | 1 | 6.6 | 6.8 | 10.87 | 3.3 | 2 | 12.6 | 2.5 | 3 | 11.30 | 1.5 |
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