BenchReference / Drill sizes / 5.1 mm 5.1 mm Drill Decimal inches 0.2008″
Millimeters 5.1 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 13/64″ 0.2031″ / 5.159 mm +0.059 mm (+0.0023″)
Number (wire gauge) #7 0.2010″ / 5.105 mm +0.005 mm (+0.0002″)
Letter A 0.2340″ / 5.944 mm +0.844 mm (+0.0332″)
−0.408 mm +0.408 mm 5.1 mm 4.9 mm −0.2 mm 5 mm −0.1 mm 5.2 mm +0.1 mm 5.3 mm +0.2 mm #7 +0.005 mm 13/64″ +0.059 mm A +0.844 mm → tick position = true diameter · metric neighbors above, equivalents below · window ±0.41 mm
Positive difference = cuts a slightly larger hole than 5.1 mm. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Neighboring metric sizes Drill Decimal in mm vs 5.1 mm 4.9 mm 0.1929 4.9 −0.2 mm 5 mm 0.1969 5 −0.1 mm 5.1 mm 0.2008 5.1 — 5.2 mm 0.2047 5.2 +0.1 mm 5.3 mm 0.2087 5.3 +0.2 mm
← 5 mm (smaller) 5.2 mm (larger) →
Compare 5.1 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 5.1 mm. See all data sources .