BenchReference / Drill sizes / 16 mm 16 mm Drill Decimal inches 0.6299″
Millimeters 16 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 5/8″ 0.6250″ / 15.875 mm −0.125 mm (−0.0049″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −10.209 mm (−0.4019″)
Letter Z 0.4130″ / 10.49 mm −5.51 mm (−0.2169″)
−1.28 mm +1.28 mm 16 mm 15 mm −1 mm 15.5 mm −0.5 mm 16.5 mm +0.5 mm 17 mm +1 mm 5/8″ −0.125 mm ← #1 −10.209 mm ← Z −5.51 mm tick position = true diameter · metric neighbors above, equivalents below · window ±1.28 mm
Positive difference = cuts a slightly larger hole than 16 mm. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Neighboring metric sizes Drill Decimal in mm vs 16 mm 15 mm 0.5906 15 −1 mm 15.5 mm 0.6102 15.5 −0.5 mm 16 mm 0.6299 16 — 16.5 mm 0.6496 16.5 +0.5 mm 17 mm 0.6693 17 +1 mm
← 15.5 mm (smaller) 16.5 mm (larger) →
Compare 16 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 16 mm. See all data sources .