BenchReference

#13 Drill Bit

Decimal inches 0.1850″
Millimeters 4.699 mm
System Number (wire gauge)

Nearest equivalents in other systems

System Nearest drill Size Difference
Metric 4.7 mm 0.1850″ / 4.7 mm +0.001 mm (+0.0000″)
Fractional inch 3/16″ 0.1875″ / 4.762 mm +0.063 mm (+0.0025″)
Letter A 0.2340″ / 5.944 mm +1.245 mm (+0.0490″)
−0.376 mm+0.376 mm#13#15−0.127 mm#14−0.076 mm#12+0.102 mm#11+0.152 mm4.7 mm+0.001 mm3/16″+0.063 mmA +1.245 mm →tick position = true diameter · number neighbors above, equivalents below · window ±0.38 mm
Positive difference = cuts a slightly larger hole than #13. Sizes beyond the window are listed with arrows — they are not close substitutes.

Clearance drill for

Thread Fit
#6-32 UNC loose
#6-40 UNF loose

Neighboring number sizes

Drill Decimal in mm vs #13
#15 0.1800 4.572 −0.127 mm
#14 0.1820 4.623 −0.076 mm
#13 0.1850 4.699 —
#12 0.1890 4.801 +0.102 mm
#11 0.1910 4.851 +0.152 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 0.1850″. See all data sources.