Weld Neck Flanges

Nominal Pipe Size

Outisde Diameter of Flange

Thickness Of Flange (mm)

Diameter of Raised Face

Diameter of Bore

Length Through Hub

Diameter of Hub at Base

Diameter of Hub at point of weight

Number of Bolt Holes

Diameter of Bolt

Diameter of Bolt Circle

O

Q

R

J

Y

X

H

P

inch

inch

mm

inch

mm

inch

mm

inch

mm

inch

mm

inch

mm

inch

mm

n

inch

mm

inch

mm

½

3½

88.9

7/16

11.

1.3/8

34.9

0.62

15.75

1.7/8

47.6

1.3/16

30.2

0.84

21.3

4

a½

12.7

2.3/8

60.3

¾

3.7/8

98.4

½

12.7

1.11/16

42.9

0.82

20.83

2.1/16

52.4

1½

38.1

1.05

26.7

4

½

12.7

2¾

69.9

1

4¼

108.0

9/16

14.3

2

50.8

1.05

26.67

2.3/16

55.6

1.15/16

49.2

1.32

33.5

4

½

12.7

3.1/8

79.4

1c

4.5/8

117.5

5/8

15.9

2½

63.5

1.38

35.05

2¼

57.2

2.5/16

58.7

1.66

42.2

4

½

12.7

3½

88.9

1½

5

127.0

11/16

17.5

2.7/8

73.0

1.61

40.89

2.7/16

61.9

2.9/16

65.1

1.90

48.3

4

½

12.7

3.7/8

98.4

2

6

152.4

¾

19.1

3.5/8

92.1

2.07

52.58

2½

63.5

3.1/16

77.8

2.38

60.4

4

5/8

15.9

4¾

120.7

2½

7

177.8

7/8

22.2

4.1/8

104.8

2.47

62.75

2¾

69.9

3.9/16

90.8

2.88

73.1

4

5/8

15.9

5½

139.7

3

7½

190.5

15/16

23.8

5

127.0

3.07

77.98

2¾

69.9

4¼

108.0

3.50

88.9

4

5/8

15.9

6

152.4

3½

8½

215.9

15/16

23.8

5½

139.7

3.55

90.17

2.13/16

71.4

4.13/16

122.2

4.00

101.6

8

5/8

15.9

7

177.8

4

9

228.6

15/16

23.8

6.3/16

157.2

4.03

102.36

3

76.2

5.5/16

134.9

4.50

114.3

8

5/8

15.9

7½

190.5

5

10

254.0

15/16

23.8

7.5/16

185.7

5.05

128.27

3½

88.9

6.7/16

163.5

5.56

141.2

8

¾

19.1

8½

215.9

6

11

279.4

1

25.4

8.1/2

215.9

6.07

154.18

3½

88.9

7.9/16

192.1

6.63

168.4

8

¾

19.1

9½

241.3

8

13½

342.9

1.1/8

28.6

10.5/8

269.9

7.98

202.69

4

101.6

9.11/16

246.1

8.63

219.2

8

¾

19.1

11¾

298.5

10

16

406.4

1.3/16

30.2

12¾

323.9

10.02

254.51

4

101.6

12

304.8

10.75

273.0

12

7/8

22.2

14¼

362.0

12

19

482.6

1¼

31.8

15

381.0

12.00

304.80

4½

114.3

14.3/8

365.1

12.75

323.8

12

7/8

22.2

17

431.8

14

21

533.4

1.3/8

34.9

16¼

412.8

13.25

336.55

5

127.0

15¾

400.1

14.00

355.6

12

1

25.4

18¾

476.3

16

23½

596.9

1.7/16

36.5

18½

469.9

15.25

387.35

5

127.0

18

457.2

16.00

406.4

16

1

25.4

21¼

539.8

18

25

635.0

1.9/16

39.7

21

533.4

17.25

438.15

5½

139.7

19.7/8

504.8

18.00

457.2

16

1.1/8

28.6

22¾

577.9

20

27½

698.5

1.11/16

42.9

23

584.2

19.25

488.90

5.1/16

144.5

22

558.8

20.00

508.0

20

1.1/8

28.6

25

635.0

22

29½

749.3

1.13/16

46.0

25¼

641.4

21.25

539.70

5.7/8

149.2

24

609.6

22.00

558.8

20

1¼

31.8

27¼

692.0

24

32

812.8

1.7/8

47.6

27¼

692.2

23.25

590.50

6

152.4

26.1/8

663.6

24.00

609.6

20

1¼

31.8

29½

749.3