BenchReference / Drill sizes / 5.5 mm 5.5 mm Drill Decimal inches 0.2165″
Millimeters 5.5 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 7/32″ 0.2188″ / 5.556 mm +0.056 mm (+0.0022″)
Number (wire gauge) #3 0.2130″ / 5.41 mm −0.09 mm (−0.0035″)
Letter A 0.2340″ / 5.944 mm +0.444 mm (+0.0175″)
−0.44 mm +0.44 mm 5.5 mm 5.3 mm −0.2 mm 5.4 mm −0.1 mm 5.6 mm +0.1 mm 5.7 mm +0.2 mm #3 −0.09 mm 7/32″ +0.056 mm A +0.444 mm → tick position = true diameter · metric neighbors above, equivalents below · window ±0.44 mm
Positive difference = cuts a slightly larger hole than 5.5 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 5.5 mm 5.3 mm 0.2087 5.3 −0.2 mm 5.4 mm 0.2126 5.4 −0.1 mm 5.5 mm 0.2165 5.5 — 5.6 mm 0.2205 5.6 +0.1 mm 5.7 mm 0.2244 5.7 +0.2 mm
← 5.4 mm (smaller) 5.6 mm (larger) →
Compare 5.5 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 5.5 mm. See all data sources .