SIZE: 12ss=3.00-3.20mm/0.12 in.
SIZE:16ss=3.80-4.00mm/0.15-0.16in.
SIZE:20ss=4.60-4.80mm / 0.18-0.19in.
SIZE:30ss=6.32-6.50mm / 0.25-0.26in.
SIZE:40ss=8.41-8.67mm/0.33-0.34 inches
