BenchReference

17/32″ Drill Bit

Decimal inches 0.5313″
Millimeters 13.494 mm
System Fractional inch
In 64ths 34/64″

Nearest equivalents in other systems

System Nearest drill Size Difference
Metric 13.5 mm 0.5315″ / 13.5 mm +0.006 mm (+0.0002″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −7.703 mm (−0.3032″)
Letter Z 0.4130″ / 10.49 mm −3.004 mm (−0.1182″)
−1.079 mm+1.079 mm17/32″1/2″−0.794 mm33/64″−0.397 mm35/64″+0.397 mm9/16″+0.794 mm13.5 mm+0.006 mm← #1 −7.703 mm← Z −3.004 mmtick position = true diameter · fractional neighbors above, equivalents below · window ±1.08 mm
Positive difference = cuts a slightly larger hole than 17/32″. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
5/8″-11 UNC 0.6250″ / 15.875 mm 11 TPI

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

Clearance drill for

Thread Fit
1/2″-13 UNC close
1/2″-20 UNF close

Neighboring fractional sizes

Drill Decimal in mm vs 17/32″
1/2″ 0.5000 12.7 −0.794 mm
33/64″ 0.5156 13.097 −0.397 mm
17/32″ 0.5313 13.494 —
35/64″ 0.5469 13.891 +0.397 mm
9/16″ 0.5625 14.287 +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 0.5313″. See all data sources.