BenchReference / Drill sizes / 9.7 mm 9.7 mm Drill Decimal inches 0.3819″
Millimeters 9.7 mm
System Metric
Nearest equivalents in other systems System Nearest drill Size Difference Fractional inch 3/8″ 0.3750″ / 9.525 mm −0.175 mm (−0.0069″)
Number (wire gauge) #1 0.2280″ / 5.791 mm −3.909 mm (−0.1539″)
Letter W 0.3860″ / 9.804 mm +0.104 mm (+0.0041″)
−0.776 mm +0.776 mm 9.7 mm 9.5 mm −0.2 mm 9.6 mm −0.1 mm 9.8 mm +0.1 mm 9.9 mm +0.2 mm 3/8″ −0.175 mm W +0.104 mm ← #1 −3.909 mm tick position = true diameter · metric neighbors above, equivalents below · window ±0.78 mm
Positive difference = cuts a slightly larger hole than 9.7 mm. Sizes
beyond the window are listed with arrows — they are not close substitutes.
Neighboring metric sizes Drill Decimal in mm vs 9.7 mm 9.5 mm 0.3740 9.5 −0.2 mm 9.6 mm 0.3780 9.6 −0.1 mm 9.7 mm 0.3819 9.7 — 9.8 mm 0.3858 9.8 +0.1 mm 9.9 mm 0.3898 9.9 +0.2 mm
← 9.6 mm (smaller) 9.8 mm (larger) →
Compare 9.7 mm with another size
Data provenance. ASME B94.11M, Twist Drills (standard drill size series) (ASME). Millimeter and inch values are converted with the exact definition 1 in = 25.4 mm; the canonical dimension for this metric size is 9.7 mm. See all data sources .