BenchReference

8.8 mm Drill

Decimal inches 0.3465″
Millimeters 8.8 mm
System Metric

Nearest equivalents in other systems

System Nearest drill Size Difference
Fractional inch 11/32″ 0.3438″ / 8.731 mm −0.069 mm (−0.0027″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −3.009 mm (−0.1185″)
Letter S 0.3480″ / 8.839 mm +0.039 mm (+0.0015″)
−0.704 mm+0.704 mm8.8 mm8.6 mm−0.2 mm8.7 mm−0.1 mm8.9 mm+0.1 mm9 mm+0.2 mm11/32″−0.069 mmS+0.039 mm← #1 −3.009 mmtick position = true diameter · metric neighbors above, equivalents below · window ±0.7 mm
Positive difference = cuts a slightly larger hole than 8.8 mm. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
M10 × 1.25 0.3937″ / 10 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 8.8 mm
8.6 mm 0.3386 8.6 −0.2 mm
8.7 mm 0.3425 8.7 −0.1 mm
8.8 mm 0.3465 8.8 —
8.9 mm 0.3504 8.9 +0.1 mm
9 mm 0.3543 9 +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 8.8 mm. See all data sources.