Table 1
Use Drill Bit
1/4"–5/16", 6mm–8mm, Z/10–A/13
5/64", 2mm
3/8"–1/2", 10mm–12mm, B/17
9/64", 3.5mm
9/16"–3/4", 15mm–18mm, C/22
13/64", 5mm