BenchReference / Drill sizes / 4.1 mm 4.1 mm Drill Decimal inches 0.1614″
Millimeters 4.1 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 5/32″ 0.1563″ / 3.969 mm −0.131 mm (−0.0052″)
Number (wire gauge) #20 0.1610″ / 4.089 mm −0.011 mm (−0.0004″)
Letter A 0.2340″ / 5.944 mm +1.844 mm (+0.0726″)
−0.328 mm +0.328 mm 4.1 mm 3.9 mm −0.2 mm 4 mm −0.1 mm 4.2 mm +0.1 mm 4.3 mm +0.2 mm 5/32″ −0.131 mm #20 −0.011 mm A +1.844 mm → tick position = true diameter · metric neighbors above, equivalents below · window ±0.33 mm
Positive difference = cuts a slightly larger hole than 4.1 mm. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Neighboring metric sizes Drill Decimal in mm vs 4.1 mm 3.9 mm 0.1535 3.9 −0.2 mm 4 mm 0.1575 4 −0.1 mm 4.1 mm 0.1614 4.1 — 4.2 mm 0.1654 4.2 +0.1 mm 4.3 mm 0.1693 4.3 +0.2 mm
← 4 mm (smaller) 4.2 mm (larger) →
Compare 4.1 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 4.1 mm. See all data sources .