BenchReference

#1 Drill Bit

Decimal inches 0.2280″
Millimeters 5.791 mm
System Number (wire gauge)

Nearest equivalents in other systems

System Nearest drill Size Difference
Metric 5.8 mm 0.2283″ / 5.8 mm +0.009 mm (+0.0003″)
Fractional inch 15/64″ 0.2344″ / 5.953 mm +0.162 mm (+0.0064″)
Letter A 0.2340″ / 5.944 mm +0.152 mm (+0.0060″)
−0.463 mm+0.463 mm#1#3−0.381 mm#2−0.178 mm5.8 mm+0.009 mmA+0.152 mm15/64″+0.162 mmtick position = true diameter · number neighbors above, equivalents below · window ±0.46 mm
Positive difference = cuts a slightly larger hole than #1. Sizes beyond the window are listed with arrows — they are not close substitutes.

Neighboring number sizes

Drill Decimal in mm vs #1
#3 0.2130 5.41 −0.381 mm
#2 0.2210 5.613 −0.178 mm
#1 0.2280 5.791 —
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 number size is 0.2280″. See all data sources.