UNF Threads
UNF (Unified National Fine) threads are standardized screw threads with a finer pitch than UNC threads. These threads are commonly used in automotive, aerospace, and hydraulic systems where high precision and a stronger hold are needed. Their finer pitch helps provide better stress distribution and vibration resistance in high-pressure environments.
| Thread | D (mm) | d (mm) | JIC Size | SAE Size |
|---|---|---|---|---|
| 7/16-20UNF | 11.07 | 10.00 | -4 | -4 |
| 1/2-20UNF | 12.70 | 11.60 | -5 | -5 |
| 9/16-18UNF | 14.25 | 13.00 | -6 | -6 |
| 5/8-18UNF | 15.85 | 14.70 | -6 | -6 |
| 3/4-16UNF | 19.00 | 17.60 | -8 | -8 |
| 7/8-14UNF | 22.17 | 20.50 | -10 | -10 |
| 1-1/16-12UN | 26.95 | 25.00 | -12 | -12 |
| 1-1/16-14UNS | 26.95 | 25.30 | -12 | -12 |
| 1-5/16-12UN | 33.30 | 31.30 | -16 | - |
| 1-5/16-14UNS | 33.30 | 31.50 | -16 | - |
| 1-5/8-12UN | 41.22 | 39.20 | -20 | - |
| 1-5/8-14UNS | 41.22 | 39.50 | -20 | - |
| 1-7/8-12UN | 47.57 | 45.60 | -24 | - |
| 1-7/8-14UNS | 47.57 | 45.90 | -24 | - |
| 2-1/2-12UN | 63.45 | 61.50 | -32 | - |
| 3-12UN | 76.20 | 74.30 | -40 | - |
| 3-1/2-12UN | 88.90 | 87.00 | -48 | - |
Specifications
- • Unified thread standard (UNF/UNS) with finer pitch
- • Diameter range: 11.07 mm to 88.90 mm
- • Compatible with JIC and SAE standards
- • Precise and tight fit for high-vibration environments
- • Manufactured as per ASME B1.1 specifications
Features
- • Finer thread pitch increases resistance to loosening under vibration
- • Suitable for high-pressure hydraulic applications
- • Available in various alloys: Carbon Steel, Stainless Steel, Brass
- • High thread engagement for superior strength
Applications
- • Hydraulic Systems: Reliable sealing in hydraulic fittings and adapters
- • Automotive Industry: Used in fuel systems, braking systems, and engine components
- • Aerospace: Vibration-resistant joints in aircraft assemblies
- • Industrial Machinery: Connections where precise sealing is critical
- • Oil & Gas: JIC/SAE-based systems requiring high-strength threading