Inch values are official. Aviation is designed and worked in inches. Millimetres are converted and are not official; where one is shown, the metric drill is the nearest alternative, not the official drill.
Specification
Where to buy| Item | Value |
|---|---|
| Type | Twist drill |
| Point | — |
| Material | High speed steel |
| Use for | The standard for metal; short shank for tight spots |
| Do not use for | — |
A dash means the sources do not state it.
Sizes
| Size | For | Inches (official) | mm (converted, not official) | Nearest metric alternative, mm |
|---|---|---|---|---|
| 3/32 in | Work, 3/32 rivet | 0.09375 in | 2.381 | 2.40 |
| #40 | Final, 3/32 rivet | 0.0980 in | 2.489 | 2.50 |
| 1/8 in | Work, 1/8 rivet | 0.1250 in | 3.175 | 3.15 or 3.20 |
| #30 | Final, 1/8 rivet | 0.1285 in | 3.264 | 3.25 |
| 5/32 in | Work, 5/32 rivet | 0.15625 in | 3.969 | 3.95 |
| #21 | Final, 5/32 rivet | 0.1590 in | 4.039 | 4.05 |
| 3/16 in | Work, 3/16 rivet | 0.1875 in | 4.763 | 4.75 |
| #11 | Final, 3/16 rivet | 0.1910 in | 4.851 | 4.85 |
| 1/4 in | Work, 1/4 rivet | 0.2500 in | 6.350 | 6.35 |
| F | Final, 1/4 rivet | 0.2570 in | 6.528 | 6.55 |
Exact mm = inches × 25.4. The alternative is the nearest 0.05 mm step: commonly used where inch drills cannot be bought, NOT the official drill. The manual sets the tolerance.
Notes
- Sold in number, letter and fractional sizes; lengths are not given by the FAA sources.
Where to buy
AmericaDistributor coming soonOur partner for this region is on its way
EuropeDistributor coming soonOur partner for this region is on its way
OceaniaDistributor coming soonOur partner for this region is on its way
Distributors coming soon.
Sources
- FAA-H-8083-31, AMT Handbook, Airframe, Volume 1 (rev. A) — pp. 4-17, fig. 4-45, fig. 4-90 (p. 4-40)
Educational reference only. not approved data. Always consult the applicable SRM, AMM, or AC 43.13-1B and your certifying authority.