BenchReference

12.5 mm Drill

Decimal inches 0.4921″
Millimeters 12.5 mm
System Metric

Nearest equivalents in other systems

System Nearest drill Size Difference
Fractional inch 31/64″ 0.4844″ / 12.303 mm −0.197 mm (−0.0078″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −6.709 mm (−0.2641″)
Letter Z 0.4130″ / 10.49 mm −2.01 mm (−0.0791″)
−1 mm+1 mm12.5 mm12.3 mm−0.2 mm12.4 mm−0.1 mm12.6 mm+0.1 mm12.7 mm+0.2 mm31/64″−0.197 mm← #1 −6.709 mm← Z −2.01 mmtick position = true diameter · metric neighbors above, equivalents below · window ±1.0 mm
Positive difference = cuts a slightly larger hole than 12.5 mm. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
M14 × 1.5 0.5512″ / 14 mm 1.5 mm

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

Neighboring metric sizes

Drill Decimal in mm vs 12.5 mm
12.3 mm 0.4843 12.3 −0.2 mm
12.4 mm 0.4882 12.4 −0.1 mm
12.5 mm 0.4921 12.5 —
12.6 mm 0.4961 12.6 +0.1 mm
12.7 mm 0.5000 12.7 +0.2 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 metric size is 12.5 mm. See all data sources.