BenchReference

#42 Drill Bit

Decimal inches 0.0935″
Millimeters 2.375 mm
System Number (wire gauge)

Nearest equivalents in other systems

System Nearest drill Size Difference
Metric 2.4 mm 0.0945″ / 2.4 mm +0.025 mm (+0.0010″)
Fractional inch 3/32″ 0.0938″ / 2.381 mm +0.006 mm (+0.0002″)
Letter A 0.2340″ / 5.944 mm +3.569 mm (+0.1405″)
−0.19 mm+0.19 mm#42#43−0.114 mm#41+0.064 mm#40+0.114 mm3/32″+0.006 mm2.4 mm+0.025 mm← #44 −0.191 mmA +3.569 mm →tick position = true diameter · number neighbors above, equivalents below · window ±0.19 mm
Positive difference = cuts a slightly larger hole than #42. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
#4-48 UNF 0.1120″ / 2.845 mm 48 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 #42
#44 0.0860 2.184 −0.191 mm
#43 0.0890 2.261 −0.114 mm
#42 0.0935 2.375 —
#41 0.0960 2.438 +0.064 mm
#40 0.0980 2.489 +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 0.0935″. See all data sources.