BenchReference

19.5 mm Drill

Decimal inches 0.7677″
Millimeters 19.5 mm
System Metric

Nearest equivalents in other systems

System Nearest drill Size Difference
Fractional inch 49/64″ 0.7656″ / 19.447 mm −0.053 mm (−0.0021″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −13.709 mm (−0.5397″)
Letter Z 0.4130″ / 10.49 mm −9.01 mm (−0.3547″)
−1.56 mm+1.56 mm19.5 mm18.5 mm−1 mm19 mm−0.5 mm20 mm+0.5 mm20.5 mm+1 mm49/64″−0.053 mm← #1 −13.709 mm← Z −9.01 mmtick position = true diameter · metric neighbors above, equivalents below · window ±1.56 mm
Positive difference = cuts a slightly larger hole than 19.5 mm. Sizes beyond the window are listed with arrows — they are not close substitutes.

Tap drill for

Thread Major diameter Pitch
M22 × 2.5 0.8661″ / 22 mm 2.5 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 19.5 mm
18.5 mm 0.7283 18.5 −1 mm
19 mm 0.7480 19 −0.5 mm
19.5 mm 0.7677 19.5 —
20 mm 0.7874 20 +0.5 mm
20.5 mm 0.8071 20.5 +1 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 19.5 mm. See all data sources.