BenchReference

10.8 mm Drill

Decimal inches 0.4252″
Millimeters 10.8 mm
System Metric

Nearest equivalents in other systems

System Nearest drill Size Difference
Fractional inch 27/64″ 0.4219″ / 10.716 mm −0.084 mm (−0.0033″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −5.009 mm (−0.1972″)
Letter Z 0.4130″ / 10.49 mm −0.31 mm (−0.0122″)
−0.864 mm+0.864 mm10.8 mm10.6 mm−0.2 mm10.7 mm−0.1 mm10.9 mm+0.1 mm11 mm+0.2 mmZ−0.31 mm27/64″−0.084 mm← #1 −5.009 mmtick position = true diameter · metric neighbors above, equivalents below · window ±0.86 mm
Positive difference = cuts a slightly larger hole than 10.8 mm. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
M12 × 1.25 0.4724″ / 12 mm 1.25 mm

The standard chart recommendation (≈75% thread engagement). Application-specific factors — material, hole depth, tap type — can justify a different drill.

Neighboring metric sizes

Drill Decimal in mm vs 10.8 mm
10.6 mm 0.4173 10.6 −0.2 mm
10.7 mm 0.4213 10.7 −0.1 mm
10.8 mm 0.4252 10.8 —
10.9 mm 0.4291 10.9 +0.1 mm
11 mm 0.4331 11 +0.2 mm
Data provenance. ASME B94.11M, Twist Drills (standard drill size series) (ASME). Machinery’s Handbook — tap drill charts (Industrial Press). Millimeter and inch values are converted with the exact definition 1 in = 25.4 mm; the canonical dimension for this metric size is 10.8 mm. See all data sources.