Bảng tra kích thước ren hệ inch - tiêu chuẩn NPTF

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

27

0.940

1/4" - 18 NPTF

13.577

10.70

18

1.411

3/8" - 18 NPTF

17.016

14.10

18

1.411

1/2" - 14 NPTF

21.211

17.40

14

1.814

3/4" - 14 NPTF

26.566

22.60

14

1.814

1" - 11 1/2 NPTF

33.195

28.50

11.5

2.209

1 1/4" - 11 1/2 NPTF

41.952

37.00

11.5

2.209

1 1/2" - 11 1/2 NPTF

48.021

43.50

11.5

2.209

2" - 11 1/2 NPTF

60.060

55.00

11.5

2.209

2 1/2" - 8 NPTF

72.642

65.50

8

3.175

4" - 8 NPTF

113.913

107.00

8

3.175