齿距
pitch
型号
size
内直经
coil diameter
建议最大装订厚度recommended
maximum book thickness
3:1
1/4”
6.4mm
4.8mm
5/16”
7.9mm
3/8”
9.5mm
7/16”
11.1mm
1/2”
12.7mm
9/16”
14.3mm
2:1
5/8”
16.0mm
3/4”
19.0mm
17.5mm
7/8”
22.0mm
20.6mm
1”
25.4mm
23.8mm