UNC · cutting tap · nominal dimensions
7/16-14 UNC
tap drill size.
For 7/16-14 UNC, the reference drill is U: 0.3680 in (9.347 mm).
The reference value is kept separate from the 70% and 75% calculated targets. Actual fit still depends on thread class, tool, material, runout, and the hole you really make.
Detail A · basic 60° profile
What the percentage describes.
“Theoretical full thread %” is radial thread height from nominal geometry. It is not axial engagement length and not a fit-class acceptance measurement.
Real drill alternatives
Neighboring sizes.
These are diameter neighbors, not silent recommendations. A positive delta makes a larger hole and a lower nominal theoretical percentage; a negative delta does the opposite.
| Bit | System | Diameter | Delta | Calculated full thread |
|---|---|---|---|---|
| 9.3 mm | metric | 0.3661 in / 9.3 mm | -0.0019 in | 76.9% |
| 9.4 mm | metric | 0.3701 in / 9.4 mm | +0.0021 in | 72.7% |
| 9.2 mm | metric | 0.3622 in / 9.2 mm | -0.0058 in | 81.1% |
| 9.5 mm | metric | 0.3740 in / 9.5 mm | +0.0060 in | 68.4% |
| 3/8 | fractional | 3/8 in / 9.525 mm | +0.0070 in | 67.4% |
| 23/64 | fractional | 23/64 in / 9.128 mm | -0.0086 in | 84.2% |
Why 3D is useful here
A thread is a helix, not a row of triangles.
Load a draggable cutaway to see the continuous internal thread. Exact diameter and profile comparisons remain in the 2D drawing above.
Evidence and limits
Why this row says cross-checked.
Tap-drill row: Rows tagged with this source were matched to a named 65% or 75% cutting-tap column. The discrete drill can calculate to a slightly different percentage from nominal dimensions.
60° geometry: Public primary reference for Unified and metric 60-degree thread geometry. The percentage-thread equation is a theoretical basic-profile calculation, not a fit or torque guarantee.
Open National Institute of Standards and Technology geometry source
The repository also records 11 source records and a dataset version on every page.