BenchReference

37/64″ Drill Bit

Decimal inches 0.5781″
Millimeters 14.684 mm
System Fractional inch

Nearest equivalents in other systems

System Nearest drill Size Difference
Metric 14.5 mm 0.5709″ / 14.5 mm −0.184 mm (−0.0073″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −8.893 mm (−0.3501″)
Letter Z 0.4130″ / 10.49 mm −4.194 mm (−0.1651″)
−1.175 mm+1.175 mm37/64″35/64″−0.794 mm9/16″−0.397 mm19/32″+0.397 mm39/64″+0.794 mm14.5 mm−0.184 mm← #1 −8.893 mm← Z −4.194 mmtick position = true diameter · fractional neighbors above, equivalents below · window ±1.17 mm
Positive difference = cuts a slightly larger hole than 37/64″. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
5/8″-18 UNF 0.6250″ / 15.875 mm 18 TPI

The standard chart recommendation (≈75% thread engagement). Application-specific factors — material, hole depth, tap type — can justify a different drill.

Neighboring fractional sizes

Drill Decimal in mm vs 37/64″
35/64″ 0.5469 13.891 −0.794 mm
9/16″ 0.5625 14.287 −0.397 mm
37/64″ 0.5781 14.684 —
19/32″ 0.5938 15.081 +0.397 mm
39/64″ 0.6094 15.478 +0.794 mm
Data provenance. ASME B94.11M, Twist Drills (standard drill size series) (ASME). Machinery’s Handbook — tap drill charts (Industrial Press). Millimeter and inch values are converted with the exact definition 1 in = 25.4 mm; the canonical dimension for this fractional size is 0.5781″. See all data sources.