#43 Drill Bit

Decimal inches 0.0890″

Millimeters 2.261 mm

System Number (wire gauge)

Nearest equivalents in other systems

System	Nearest drill	Size	Difference
Metric	2.3 mm	0.0906″ / 2.3 mm	+0.039 mm (+0.0016″)
Fractional inch	3/32″	0.0938″ / 2.381 mm	+0.121 mm (+0.0047″)
Letter	A	0.2340″ / 5.944 mm	+3.683 mm (+0.1450″)

Positive difference = cuts a slightly larger hole than #43. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread	Major diameter	Pitch
#4-40 UNC	0.1120″ / 2.845 mm	40 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
#1-64 UNC	normal
#1-72 UNF	normal

Neighboring number sizes

Drill	Decimal in	mm	vs #43
#45	0.0820	2.083	−0.178 mm
#44	0.0860	2.184	−0.076 mm
#43	0.0890	2.261	—
#42	0.0935	2.375	+0.114 mm
#41	0.0960	2.438	+0.178 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 0.0890″. See all data sources.