水管用的大小單位是吋(英吋)
一般配電用管，厚度2mm
一般配水用管，厚度3mm 或 3.5mm
口徑
|
管徑 厘米(公制)
|
管徑 吋(英吋)
|
管徑 吋(英吋)
|
1分
|
1/8"
|
||
2分
|
6mm
|
2/8"
|
|
3分
|
12mm
|
||
13mm
|
3/8"
|
||
4分
|
16mm
|
1/2"
|
½"
|
6分
|
20mm
|
3/4"
|
¾
|
1吋
|
27mm
|
1"
|
1"
|
35mm
|
1 1/4"
|
1¼
|
|
1吋半
|
40mm
|
1 1/2"
|
1½"
|
2吋
|
50mm
|
2"
|
2"
|
2吋半
|
65mm
|
2 1/2"
|
2½"
|
80mm
|
3"
|
3"
|
|
90mm
|
3 1/2"
|
3½"
|
|
100mm
|
4"
|
4"
|
|
125mm
|
5"
|
5"
|
|
148mm
|
6"
|
6"
|
|
194mm
|
8"
|
8"
|
|
240mm
|
10"
|
10"
|
|
286mm
|
12"
|
12"
|
