#19 Drill Bit Size
A #19 drill bit is 0.1660 inches or 4.22 mm. It falls between 5/32 inch and 11/64 inch, with 11/64 inch slightly larger.
Quick Answer
Decimal
0.1660 in
Metric
4.22 mm
Closest
11/64 inch
#19 Drill Bit Equivalent Chart
| Size | Decimal Inches | Metric | Note |
|---|---|---|---|
| #19 | 0.1660 in | 4.22 mm | Exact size |
| 11/64 inch | 0.1719 in | 4.37 mm | Closest common fractional oversize |
| 5/32 inch | 0.1563 in | 3.97 mm | Common fractional undersize |
| 4.2 mm | 0.1654 in | 4.20 mm | Nearby metric size |
Common Uses
Tap drilling and precision hole sizing for machine-screw applications.
Exact vs Nearest Size
Choose the exact bit for threads, tight hardware fits, dowels, and precision layouts. Use the nearest common equivalent only for rough pilot holes, clearance holes, or material removal where a slight difference is acceptable.
#19 Drill Bit FAQ
What are the inch and metric dimensions for #19?
#19 drill bit measures 0.1660 in and 4.22 mm.
What is the closest common equivalent to #19?
11/64 inch is the closest common equivalent listed here. It measures 0.1719 in or 4.37 mm.
Can I substitute another bit for #19?
Use the exact bit size for tap drilling, precision holes, dowels, and manufacturer-specified hardware. A nearby fractional, metric, numbered, or letter drill bit is usually fine only for clearance holes or rough pilot holes.