BẢNG TRA KÍCH THƯỚC REN HỆ INCH -TIÊU CHUẨN UNEF
Nominal Diameter
Major Diameter mm
Tapping Drill Size mm
TPI
Pitch mm
1/16" - 27 NPTF
7.870
6.00
27
0.940
1/8" - 27 NPTF
10.217
8.25
1/4" - 18 NPTF
13.577
10.70
18
1.411
3/8" - 18 NPTF
17.016
14.10
1/2" - 14 NPTF
21.211
17.40
14
1.814
3/4" - 14 NPTF
26.566
22.60
1" - 11 1/2 NPTF
33.195
28.50
11.5
2.209
1 1/4" - 11 1/2 NPTF
41.952
37.00
1 1/2" - 11 1/2 NPTF
48.021
43.50
2" - 11 1/2 NPTF
60.060
55.00
2 1/2" - 8 NPTF
72.642
65.50
8
3.175
4" - 8 NPTF
113.913
107.00