BenchReference / Drill sizes / 3.8 mm 3.8 mm Drill Decimal inches 0.1496″
Millimeters 3.8 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 5/32″ 0.1563″ / 3.969 mm +0.169 mm (+0.0066″)
Number (wire gauge) #25 0.1495″ / 3.797 mm −0.003 mm (−0.0001″)
Letter A 0.2340″ / 5.944 mm +2.144 mm (+0.0844″)
−0.304 mm +0.304 mm 3.8 mm 3.6 mm −0.2 mm 3.7 mm −0.1 mm 3.9 mm +0.1 mm 4 mm +0.2 mm #25 −0.003 mm 5/32″ +0.169 mm A +2.144 mm → tick position = true diameter · metric neighbors above, equivalents below · window ±0.3 mm
Positive difference = cuts a slightly larger hole than 3.8 mm. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Neighboring metric sizes Drill Decimal in mm vs 3.8 mm 3.6 mm 0.1417 3.6 −0.2 mm 3.7 mm 0.1457 3.7 −0.1 mm 3.8 mm 0.1496 3.8 — 3.9 mm 0.1535 3.9 +0.1 mm 4 mm 0.1575 4 +0.2 mm
← 3.7 mm (smaller) 3.9 mm (larger) →
Compare 3.8 mm with another size
Data provenance. ASME B94.11M, Twist Drills (standard drill size series) (ASME). Millimeter and inch values are converted with the exact definition 1 in = 25.4 mm; the canonical dimension for this metric size is 3.8 mm. See all data sources .