BenchReference / Drill sizes / 4.5 mm 4.5 mm Drill Decimal inches 0.1772″
Millimeters 4.5 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 11/64″ 0.1719″ / 4.366 mm −0.134 mm (−0.0053″)
Number (wire gauge) #16 0.1770″ / 4.496 mm −0.004 mm (−0.0002″)
Letter A 0.2340″ / 5.944 mm +1.444 mm (+0.0568″)
−0.36 mm +0.36 mm 4.5 mm 4.3 mm −0.2 mm 4.4 mm −0.1 mm 4.6 mm +0.1 mm 4.7 mm +0.2 mm 11/64″ −0.134 mm #16 −0.004 mm A +1.444 mm → tick position = true diameter · metric neighbors above, equivalents below · window ±0.36 mm
Positive difference = cuts a slightly larger hole than 4.5 mm. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Clearance drill for Neighboring metric sizes Drill Decimal in mm vs 4.5 mm 4.3 mm 0.1693 4.3 −0.2 mm 4.4 mm 0.1732 4.4 −0.1 mm 4.5 mm 0.1772 4.5 — 4.6 mm 0.1811 4.6 +0.1 mm 4.7 mm 0.1850 4.7 +0.2 mm
← 4.4 mm (smaller) 4.6 mm (larger) →
Compare 4.5 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 4.5 mm. See all data sources .