BenchReference

#25 Drill Bit

Decimal inches 0.1495″
Millimeters 3.797 mm
System Number (wire gauge)

Nearest equivalents in other systems

System Nearest drill Size Difference
Metric 3.8 mm 0.1496″ / 3.8 mm +0.003 mm (+0.0001″)
Fractional inch 5/32″ 0.1563″ / 3.969 mm +0.171 mm (+0.0068″)
Letter A 0.2340″ / 5.944 mm +2.146 mm (+0.0845″)
−0.304 mm+0.304 mm#25#27−0.14 mm#26−0.063 mm#24+0.064 mm#23+0.114 mm3.8 mm+0.003 mm5/32″+0.171 mmA +2.146 mm →tick position = true diameter · number neighbors above, equivalents below · window ±0.3 mm
Positive difference = cuts a slightly larger hole than #25. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
#10-24 UNC 0.1900″ / 4.826 mm 24 TPI

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

Neighboring number sizes

Drill Decimal in mm vs #25
#27 0.1440 3.658 −0.14 mm
#26 0.1470 3.734 −0.063 mm
#25 0.1495 3.797 —
#24 0.1520 3.861 +0.064 mm
#23 0.1540 3.912 +0.114 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 number size is 0.1495″. See all data sources.