1″-12 UNF Thread
Recommended tap drill 59/64″
Tap drill Ø 0.9219″ / 23.416 mm
Major Ø 1.0000″ / 25.4 mm
Threads per inch 12
The chart recommendation gives approximately 72.2% thread engagement — the conventional target for average materials. It is not the only valid choice; see the options below.
Specification
| Designation | 1″-12 UNF |
|---|---|
| Thread family | Unified National Fine (UNF) |
| Nominal size | 1 |
| Basic major diameter | 1.0000″ / 25.4 mm |
| Threads per inch / pitch | 12 TPI (2.117 mm pitch) |
| Recommended tap drill | 59/64″ (0.9219″ / 23.416 mm) |
Clearance holes
For a bolt or screw of this size to pass through freely. Recommended drills per ASME B18.2.8: close, normal, and loose fits.
| Fit | Drill / Ø | Decimal in | mm |
|---|---|---|---|
| close | 1-1/32″ | 1.0313 | 26.194 |
| normal | 1-3/32″ | 1.0938 | 27.781 |
| loose | 1-5/32″ | 1.1563 | 29.369 |
Hex bolt & nut dimensions
For a standard hex cap screw (ASME B18.2.1) and finished hex nut (ASME B18.2.2) in this size.
| Wrench / socket size (bolt head) | 1-1/2″ |
|---|---|
| Head height | 39/64″ (0.6094″) |
| Nut thickness | 55/64″ (0.8594″) |
| Compatible nut | 1-12 hex nut |
Basic (nominal) dimensions. See the wrench & socket size charts for all sizes and the metric ↔ SAE socket comparison.
Related threads
- 1″-8 UNC — same nominal size, 8 TPI (Unified National Coarse (UNC)) · compare
- 7/8″-14 UNF — next size down in UNF