BenchReference / Drill sizes / M M Drill Bit Decimal inches 0.2950″
Millimeters 7.493 mm
System Letter
Nearest equivalents in other systems System Nearest drill Size Difference Metric 7.5 mm 0.2953″ / 7.5 mm +0.007 mm (+0.0003″)
Fractional inch 19/64″ 0.2969″ / 7.541 mm +0.048 mm (+0.0019″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −1.702 mm (−0.0670″)
−0.599 mm +0.599 mm M K −0.356 mm L −0.127 mm N +0.178 mm O +0.533 mm 7.5 mm +0.007 mm 19/64″ +0.048 mm ← #1 −1.702 mm tick position = true diameter · letter neighbors above, equivalents below · window ±0.6 mm
Positive difference = cuts a slightly larger hole than M. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Neighboring letter sizes Drill Decimal in mm vs M K 0.2810 7.137 −0.356 mm L 0.2900 7.366 −0.127 mm M 0.2950 7.493 — N 0.3020 7.671 +0.178 mm O 0.3160 8.026 +0.533 mm
← L (smaller) N (larger) →
Compare M 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 letter size is 0.2950″. See all data sources .