BenchReference / Drill sizes / 4.3 mm 4.3 mm Drill Decimal inches 0.1693″
Millimeters 4.3 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 11/64″ 0.1719″ / 4.366 mm +0.066 mm (+0.0026″)
Number (wire gauge) #18 0.1695″ / 4.305 mm +0.005 mm (+0.0002″)
Letter A 0.2340″ / 5.944 mm +1.644 mm (+0.0647″)
−0.344 mm +0.344 mm 4.3 mm 4.1 mm −0.2 mm 4.2 mm −0.1 mm 4.4 mm +0.1 mm 4.5 mm +0.2 mm #18 +0.005 mm 11/64″ +0.066 mm A +1.644 mm → tick position = true diameter · metric neighbors above, equivalents below · window ±0.34 mm
Positive difference = cuts a slightly larger hole than 4.3 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 4.3 mm 4.1 mm 0.1614 4.1 −0.2 mm 4.2 mm 0.1654 4.2 −0.1 mm 4.3 mm 0.1693 4.3 — 4.4 mm 0.1732 4.4 +0.1 mm 4.5 mm 0.1772 4.5 +0.2 mm
← 4.2 mm (smaller) 4.4 mm (larger) →
Compare 4.3 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 4.3 mm. See all data sources .