BenchReference

#15 Drill Bit

Decimal inches 0.1800″
Millimeters 4.572 mm
System Number (wire gauge)

Nearest equivalents in other systems

System Nearest drill Size Difference
Metric 4.6 mm 0.1811″ / 4.6 mm +0.028 mm (+0.0011″)
Fractional inch 3/16″ 0.1875″ / 4.762 mm +0.191 mm (+0.0075″)
Letter A 0.2340″ / 5.944 mm +1.372 mm (+0.0540″)
−0.366 mm+0.366 mm#15#17−0.178 mm#16−0.076 mm#14+0.051 mm#13+0.127 mm4.6 mm+0.028 mm3/16″+0.191 mmA +1.372 mm →tick position = true diameter · number neighbors above, equivalents below · window ±0.37 mm
Positive difference = cuts a slightly larger hole than #15. Sizes beyond the window are listed with arrows — they are not close substitutes.

Clearance drill for

Thread Fit
#8-32 UNC close
#8-36 UNF close

Neighboring number sizes

Drill Decimal in mm vs #15
#17 0.1730 4.394 −0.178 mm
#16 0.1770 4.496 −0.076 mm
#15 0.1800 4.572 —
#14 0.1820 4.623 +0.051 mm
#13 0.1850 4.699 +0.127 mm
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 0.1800″. See all data sources.