Welding Neck Flanges Dimensions & Weights (ASME B16.5)

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Welding Neck Flanges Dimensions & Weights (ASME B16.5)

ASME B16.5 (Flanges), Flange Dimensions & Weigths, Flange Weld-Neck

The article shows the ASME B16.5 dimensions of Weld-Neck Flanges Classes from 150 to 2500 (NPS, ID, OD, Thickness, and bolting details, tolerances) – both in inches and millimeters.

ASME WELDING NECK FLANGE DIMENSIONS & WEIGHTS

The article shows the ASME B16.5 dimensions and weights for weld-neck flanges.

WN FLANGE SIZES IN INCHES

WN CLASS 150

Weld neck flange dimensions class 150 (ASME B16.5) in inches

Flange NPS	Inside Diameter	Outside Diameter	Bolt Circle (BC)	Raised Face (R)	Raised Face (RF)	H	H1	Raised Face Thickness (T)	T1	Flat Face Thickness (T2)	Bolt Hole (B)	No. of Bolt Holes
1/2″	0.62″	3.50″	2.38″	1.38″	.063″	1.19″	0.84″	1.88″	.38″	1.82″	.62″	4
3/4″	0.82″	3.88″	2.75″	1.69″	.063″	1.50″	1.05″	2.06″	.44″	2.00″	.62″	4
1″	1.05″	4.25″	3.12″	2.00″	.063″	1.94″	1.32″	2.19″	.50″	2.13″	.62″	4
1-1/4″	1.38″	4.62″	3.50″	2.50″	.063″	2.31″	1.66″	2.25″	.56″	2.19″	.62″	4
1-1/2″	1.61″	5.00″	3.88″	2.88″	.063″	2.56″	1.90″	2.44″	.62″	2.38″	.62″	4
2″	2.07″	6.00″	4.75″	3.62″	.063″	3.06″	2.38″	2.50″	.69″	2.44″	.75″	4
2-1/2″	2.47″	7.00″	5.50″	4.12″	.063″	3.56″	2.88″	2.75″	.82″	2.69″	.75″	4
3″	3.07″	7.50″	6.00″	5.00″	.063″	4.25″	3.50″	2.75″	.88″	2.69″	.75″	4
3-1/2″	3.55″	8.50″	7.00″	5.50″	.063″	4.81″	4.00″	2.81″	.88″	2.75″	.75″	8
4″	4.03″	9.00″	7.50″	6.19″	.063″	5.31″	4.50″	3.00″	.88″	2.94″	.75″	8
5″	5.05″	10.00″	8.50″	7.31″	.063″	6.44″	5.56″	3.50″	.88″	3.44″	.88″	8
6″	6.07″	11.00″	9.50″	8.50″	.063″	7.56″	6.63″	3.50″	.94″	3.44″	.88″	8
8″	7.98″	13.50″	11.75″	10.62″	.063″	9.69″	8.63″	4.00″	1.06″	3.94″	.88″	8
10″	10.02″	16.00″	14.25″	12.75″	.063″	12.00″	10.75″	4.00″	1.13″	3.94″	1.00″	12
12″	12.00″	19.00″	17.00″	15.00″	.063″	14.38″	12.75″	4.50″	1.19″	4.44″	1.00″	12
14″	13.25″	21.00″	18.75″	16.25″	.063″	15.75″	14.00″	5.00″	1.32″	4.94″	1.12″	12
16″	15.25″	23.50″	21.25″	18.50″	.063″	18.00″	16.00″	5.00″	1.38″	4.94″	1.12″	16
18″	17.25″	25.00″	22.75″	21.00″	.063″	19.88″	18.00″	5.50″	1.50″	5.44″	1.25″	16
20″	19.25″	27.50″	25.00″	23.00″	.063″	22.00″	20.00″	5.69″	1.63″	5.63″	1.25″	20
22″	21.25″	29.50″	27.25″	25.25″	.063″	24.25″	22.00″	5.88″	1.75″	5.82″	1.38″	20
24″	23.25″	32.00″	29.50″	27.25″	.063″	26.12″	24.00″	6.00″	1.82″	5.94″	1.38″	20

WN CLASS 300

Weld neck flange dimensions class 300 (ASME B16.5) in inches

Flange NPS	Inside Diameter	Outside Diameter	Bolt Circle (BC)	Raised Face (R)	Raised Face (RF)	H	H1	Raised Face Thickness (T)	T1	Flat Face Thickness (T2)	Bolt Hole (B)	No. of Bolt Holes
1/2″	0.62″	3.75″	2.62″	1.38″	.063″	1.50″	0.84″	2.06″	.50″	2.00″	0.62″	4
3/4″	0.82″	4.62″	3.25″	1.69″	.063″	1.88″	1.05″	2.25″	.56″	2.19″	0.75″	4
1″	1.05″	4.88″	3.50″	2.00″	.063″	2.12″	1.32″	2.44″	.63″	2.38″	0.75″	4
1-1/4″	1.38″	5.25″	3.88″	2.50″	.063″	2.50″	1.66″	2.56″	.69″	2.50″	0.75″	4
1-1/2″	1.61″	6.12″	4.50″	2.88″	.063″	2.75″	1.90″	2.69″	.75″	2.63″	0.88″	4
2″	2.07″	6.50″	5.00″	3.62″	.063″	3.31″	2.38″	2.75″	.82″	2.69″	0.75″	8
2-1/2″	2.47″	7.50″	5.88″	4.12″	.063″	3.94″	2.88″	3.00″	.94″	2.94″	0.88″	8
3″	3.07″	8.25″	6.62″	5.00″	.063″	4.62″	3.50″	3.12″	1.06″	3.06″	0.88″	8
3-1/2″	3.55″	9.00″	7.25″	5.50″	.063″	5.25″	4.00″	3.19″	1.13″	3.13″	0.88″	8
4″	4.03″	10.00″	7.88″	6.19″	.063″	5.75″	4.50″	3.38″	1.19″	3.32″	0.88″	8
5″	5.05″	11.00″	9.25″	7.31″	.063″	7.00″	5.56″	3.88″	1.32″	3.82″	0.88″	8
6″	6.07″	12.50″	10.62″	8.50″	.063″	8.12″	6.63″	3.88″	1.38″	3.82″	0.88″	12
8″	7.98″	15.00″	13.00″	10.62″	.063″	10.25″	8.63″	4.38″	1.56″	4.32″	1.00″	12
10″	10.02″	17.50″	15.25″	12.75″	.063″	12.62″	10.75″	4.62″	1.82″	4.56″	1.12″	16
12″	12.00″	20.50″	17.75″	15.00″	.063″	14.75″	12.75″	5.12″	1.94″	5.06″	1.25″	16
14″	13.25″	23.00″	20.25″	16.25″	.063″	16.75″	14.00″	5.62″	2.06″	5.56″	1.25″	20
16″	15.25″	25.50″	22.50″	18.50″	.063″	19.00″	16.00″	5.75″	2.19″	5.69″	1.38″	20
18″	17.25″	28.00″	24.75″	21.00″	.063″	21.00″	18.00″	6.25″	2.32″	6.19″	1.38″	24
20″	19.25″	30.50″	27.00″	23.00″	.063″	23.12″	20.00″	6.38″	2.44″	6.32″	1.38″	24
22″	21.25″	33.00″	29.25″	25.25″	.063″	25.25″	22.00″	6.50″	2.57″	6.44″	1.62″	24
24″	23.25″	36.00″	32.0″	27.25″	.063″	27.62″	24.00″	6.62″	2.69″	6.56″	1.62″	24

WN CLASS 400

Weld neck flange dimensions class 400 (ASME B16.5) in inches

Flange NPS	Inside Diameter	Outside Diameter	Bolt Circle (BC)	Raised Face (R)	Raised Face (RF)	H	H1	Raised Face Thickness (T)	T1	Flat Face Thickness (T2)	Bolt Hole (B)	No. of Bolt Holes
1/2″	.55″	3.75″	2.62″	1.38″	.250″	1.50″	0.84″	2.31″	0.56″	2.06″	0.62″	4
3/4″	.74″	4.62″	3.25″	1.69″	.250″	1.88″	1.05″	2.50″	0.62″	2.25″	0.75″	4
1″	.96″	4.88″	3.50″	2.00″	.250″	2.12″	1.32″	2.69″	0.69″	2.44″	0.75″	4
1-1/4″	1.28″	5.25″	3.88″	2.50″	.250″	2.50″	1.66″	2.87″	0.81″	2.62″	0.75″	4
1-1/2″	1.50″	6.12″	4.50″	2.88″	.250″	2.75″	1.90″	3.00″	0.88″	2.75″	0.88″	4
2″	1.94″	6.50″	5.00″	3.62″	.250″	3.31″	2.38″	3.13″	1.00″	2.88″	0.75″	8
2-1/2″	2.32″	7.50″	5.88″	4.12″	.250″	3.94″	2.88″	3.37″	1.12″	3.12″	0.88″	8
3″	2.90″	8.25″	6.62″	5.00″	.250″	4.62″	3.50″	3.50″	1.25″	3.25″	0.88″	8
3-1/2″	3.36″	9.00″	7.25″	5.50″	.250″	5.25″	4.00″	3.63″	1.38″	3.38″	1.00″	8
4″	3.83″	10.00″	7.88″	6.19″	.250″	5.75″	4.50″	3.75″	1.38″	3.50″	1.00″	8
5″	4.81″	11.00″	9.25″	7.31″	.250″	7.00″	5.56″	4.25″	1.50″	4.00″	1.00″	8
6″	5.76″	12.50″	10.62″	8.50″	.250″	8.12″	6.63″	4.31″	1.62″	4.06″	1.00″	12
8″	7.63″	15.00″	13.00″	10.62″	.250″	10.25″	8.63″	4.87″	1.88″	4.62″	1.12″	12
10″	9.75″	17.50″	15.25″	12.75″	.250″	12.62″	10.75″	5.13″	2.12″	4.88″	1.25″	16
12″	11.75″	20.50″	17.75″	15.00″	.250″	14.75″	12.75″	5.63″	2.25″	5.38″	1.38″	16
14″	13.00″	23.00″	20.25″	16.25″	.250″	16.75″	14.00″	6.13″	2.38″	5.88″	1.38″	20
16″	15.00″	25.50″	22.50″	18.50″	.250″	19.00″	16.00″	6.25″	2.50″	6.00″	1.50″	20
18″	17.00″	28.00″	24.75″	21.00″	.250″	21.00″	18.00″	6.75″	2.62″	6.50″	1.50″	24
20″	19.00″	30.50″	27.00″	23.00″	.250″	23.12″	20.00″	6.87″	2.75″	6.62″	1.62″	24
22″	21.00″	33.00″	29.25″	25.25″	.250″	25.25″	22.00″	7.00″	2.88″	6.75″	1.75″	24
24″	23.00″	36.00″	32.00″	27.25″	.250″	27.62″	24.00″	7.13″	3.00″	6.88″	1.88″	24

WN CLASS 600

Weld neck flange dimensions class 600 (ASME B16.5) in inches

Flange NPS	Inside Diameter	Outside Diameter	Bolt Circle (BC)	Raised Face (R)	Raised Face (RF)	H	H1	Raised Face Thickness (T)	T1	Flat Face Thickness (T2)	Bolt Hole (B)	No. of Bolt Holes
1/2″	0.55″	3.75″	2.62″	1.38″	.250″	1.50″	0.84″	2.31″	0.56″	2.06″	0.62″	4
3/4″	0.74″	4.62″	3.25″	1.69″	.250″	1.88″	1.05″	2.50″	0.62″	2.25″	0.75″	4
1″	0.96″	4.88″	3.50″	2.00″	.250″	2.12″	1.32″	2.69″	0.69″	2.44″	0.75″	4
1-1/4″	1.28″	5.25″	3.88″	2.50″	.250″	2.50″	1.66″	2.87″	0.81″	2.62″	0.75″	4
1-1/2″	1.50″	6.12″	4.50″	2.88″	.250″	2.75″	1.90″	3.00″	0.88″	2.75″	0.88″	4
2″	1.94″	6.50″	5.00″	3.62″	.250″	3.31″	2.38″	3.13″	1.00″	2.88″	0.75″	8
2-1/2″	2.32″	7.50″	5.88″	4.12″	.250″	3.94″	2.88″	3.37″	1.12″	3.12″	0.88″	8
3″	2.90″	8.25″	6.62″	5.00″	.250″	4.62″	3.50″	3.50″	1.25″	3.25″	0.88″	8
3-1/2″	3.36″	9.00″	7.25″	5.50″	.250″	5.25″	4.00″	3.63″	1.38″	3.38″	1.00″	8
4″	3.83″	10.75″	8.50″	6.19″	.250″	6.00″	4.50″	4.25″	1.5″	4.00″	1.00″	8
5″	4.81″	13.00″	10.50″	7.31″	.250″	7.44″	5.56″	4.75″	1.75″	4.50″	1.12″	8
6″	5.76″	14.00″	11.50″	8.50″	.250″	8.75″	6.63″	4.87″	1.88″	4.62″	1.12″	12
8″	7.63″	16.50″	13.75″	10.62″	.250″	10.75″	8.63″	5.50″	2.19″	5.25″	1.25″	12
10″	9.75″	20.00″	17.00″	12.75″	.250″	13.5″	10.75″	6.25″	2.50″	6.00″	1.38″	16
12″	11.75″	22.00″	19.25″	15.00″	.250″	15.75″	12.75″	6.37″	2.62″	6.12″	1.38″	20
14″	13.00″	23.75″	20.75″	16.25″	.250″	17.00″	14.00″	6.75″	2.75″	6.50″	1.50″	20
16″	15.00″	27.00″	23.75″	18.50″	.250″	19.50″	16.00″	7.25″	3.00″	7.00″	1.62″	20
18″	17.00″	29.25″	25.75″	21.00″	.250″	21.50″	18.00″	7.50″	3.25″	7.25″	1.75″	20
20″	19.00″	32.00″	28.50″	23.00″	.250″	24.00″	20.00″	7.75″	3.50″	7.50″	1.75″	24
22″	21.00″	34.25″	30.63″	25.25″	.250″	26.25″	22.00″	8.00″	3.75″	7.75″	1.75″	24
24″	23.00″	37.00″	33.00″	27.25″	.250″	28.25″	24.00″	8.25″	4.00″	8.00″	2.00″	24

WN CLASS 900

Weld neck flange dimensions class 900 (ASME B16.5) in inches

Flange NPS	Inside Diameter	Outside Diameter	Bolt Circle (BC)	Raised Face (R)	Raised Face (RF)	H	H1	Raised Face Thickness (T)	T1	Flat Face Thickness (T2)	Bolt Hole (B)	No. of Bolt Holes
3″	2.90″	9.50″	7.50″	5.00″	.250″	5.00″	3.50″	4.25″	1.50″	4.00″	1.00″	8
4″	3.83″	11.50″	9.25″	6.19″	.250″	6.25″	4.50″	4.75″	1.75″	4.50″	1.25″	8
5″	4.81″	13.75″	11.00″	7.31″	.250″	7.50″	5.56″	5.25″	3.00″	5.00″	1.38″	8
6″	5.76″	15.00″	12.50″	8.50″	.250″	9.25″	6.63″	5.75″	2.19″	5.50″	1.25″	12
8″	7.63″	18.50″	15.50″	10.63″	.250″	11.75″	8.63″	6.63″	2.50″	6.38″	1.50″	12
10″	9.75″	21.50″	18.50″	12.75″	.250″	14.50″	10.75″	7.50″	2.75″	7.25″	1.50″	16
12″	11.75″	24.00″	21.00″	15.00″	.250″	16.50″	12.75″	8.13″	3.13″	7.88″	1.50″	20
14″	13.00″	25.25″	22.00″	16.25″	.250″	17.75″	14.00″	8.63″	3.38″	8.38″	1.63″	20
16″	15.00″	27.75″	24.25″	18.50″	.250″	20.00″	16.00″	8.75″	3.50″	8.50″	1.75″	20
18″	17.00″	31.00″	27.00″	21.00″	.250″	22.25″	18.00″	9.25″	4.00″	9.00″	2.00″	20
20″	19.00″	33.75″	29.50″	23.00″	.250″	24.50″	20.00″	10.00″	4.25″	9.75″	2.13″	20
24″	23.00″	41.00″	35.50″	27.25″	.250″	29.50″	24.00″	11.75″	5.50″	11.50″	2.63″	20

WN CLASS 1500

Weld neck flange dimensions class 1500 (ASME B16.5) in inches

Flange NPS	Inside Diameter	Outside Diameter	Bolt Circle (BC)	Raised Face (R)	Raised Face (RF)	H	H1	Raised Face Thickness (T)	T1	Flat Face Thickness (T2)	Bolt Hole (B)	No. of Bolt Holes
1/2″	0.55″	4.75″	3.25″	1.38″	.250″	1.50″	0.84″	2.63″	0.88″	2.38″	0.88″	4
3/4″	0.74″	5.13″	3.50″	1.69″	.250″	1.75″	1.05″	3.00″	1.00″	2.75″	0.88″	4
1″	0.96″	5.88″	4.00″	2.00″	.250″	2.06″	1.32″	3.13″	1.13″	2.88″	1.00″	4
1-1/4″	1.28″	6.25″	4.38″	2.50″	.250″	2.50″	1.66″	3.13″	1.13″	2.88″	1.00″	4
1-1/2″	1.50″	7.00″	4.88″	2.88″	.250″	2.75″	1.90″	3.50″	1.25″	3.25″	1.13″	4
2″	1.94″	8.50″	6.50″	3.63″	.250″	4.13″	2.38″	4.25″	1.50″	4.00″	1.00″	8
2-1/2″	2.32″	9.63″	7.50″	4.13″	.250″	4.88″	2.88″	4.38″	1.63″	4.13″	1.13″	8
3″	2.90″	10.50″	8.00″	5.00″	.250″	5.25″	3.50″	4.88″	1.88″	4.63″	1.25″	8
4″	3.83″	12.25″	9.50″	6.19″	.250″	6.38″	4.50″	5.13″	2.13″	4.88″	1.38″	8
5″	4.81″	14.75″	11.50″	7.31″	.250″	7.75″	5.56″	6.38″	2.88″	6.13″	1.63″	8
6″	5.76″	15.50″	12.50″	8.50″	.250″	9.00″	6.63″	7.00″	3.25″	6.75″	1.50″	12
8″	7.63″	19.00″	15.50″	10.63″	.250″	11.50″	8.63″	8.63″	3.63″	8.38″	1.75″	12
10″	9.75″	23.00″	19.00″	12.75″	.250″	14.50″	10.75″	10.25″	4.25″	10.00″	2.00″	12
12″	11.75″	26.50″	22.50″	15.00″	.250″	17.75″	12.75″	11.38″	4.88″	11.13″	2.13″	16
14″	13.00″	29.50″	25.00″	16.25″	.250″	19.50″	14.00″	12.00″	5.25″	11.75″	2.38″	16
16″	15.00″	32.50″	27.75″	18.50″	.250″	21.75″	16.00″	12.50″	5.75″	12.25″	2.63″	16
18″	17.00″	36.00″	30.50″	21.00″	.250″	23.50″	18.00″	13.13″	6.38″	12.88″	2.88″	16
20″	19.00″	38.75″	32.75″	23.00″	.250″	25.25″	20.00″	14.25″	7.00″	14.00″	3.13″	16
24″	23.00″	46.00″	39.00″	27.25″	.250″	30.00″	24.00″	16.25″	8.00″	16.00″	3.63″	16

WN CLASS 2500

Weld neck flange dimensions class 2500 (ASME B16.5) in inches

Flange NPS	Inside Diameter	Outside Diameter	Bolt Circle (BC)	Raised Face (R)	Raised Face (RF)	H	H1	Raised Face Thickness (T)	T1	Flat Face Thickness (T2)	Bolt Hole (B)	No. of Bolt Holes
1/2″	0.55″	5.25″	3.50″	1.38″	.250″	1.69″	0.84″	3.13″	1.19″	2.88″	0.88″	4
3/4″	0.74″	5.50″	3.75″	1.69″	.250″	2.00″	1.05″	3.38″	1.25″	3.13″	0.88″	4
1″	0.96″	6.25″	4.25″	2.00″	.250″	2.25″	1.32″	3.75″	1.38″	3.50″	1.00″	4
1-1/4″	1.28″	7.25″	5.13″	2.50″	.250″	2.88″	1.66″	4.00″	1.50″	3.75″	1.13″	4
1-1/2″	1.50″	8.00″	5.75″	2.88″	.250″	3.13″	1.90″	4.63″	1.75″	4.38″	1.25″	4
2″	1.94″	9.25″	6.75″	3.63″	.250″	3.75″	2.38″	5.25″	2.00″	5.00″	1.13″	8
2-1/2″	2.32″	10.50″	7.75″	4.13″	.250″	4.50″	2.88″	5.88″	2.25″	5.63″	1.25″	8
3″	2.90″	12.00″	9.00″	5.00″	.250″	5.25″	3.50″	6.88″	2.63″	6.63″	1.38″	8
4″	3.83″	14.00″	10.75″	6.19″	.250″	6.50″	4.50″	7.75″	3.00″	7.50″	1.63″	8
5″	4.81″	16.50″	12.75″	7.31″	.250″	8.00″	5.56″	9.25″	3.63″	9.00″	1.88″	8
6″	5.76″	19.00″	14.50″	8.50″	.250″	9.25″	6.63″	11.00″	4.25″	10.75″	2.13″	8
8″	7.63″	21.75″	17.25″	10.63″	.250″	12.00″	8.63″	12.75″	5.00″	12.50″	2.13″	12
10″	9.75″	26.50″	21.25″	12.75″	.250″	14.75″	10.75″	16.75″	6.50″	16.50″	2.63″	12
12″	11.75″	30.00″	24.38″	15.00″	.250″	17.38″	12.75″	18.50″	7.25″	18.25″	2.88″	12

WN FLANGE SIZES IN MILLIMETERS

WN CLASS 150

Weld neck flange dimensions class 150 (ASME B16.5) in millimeters

Size inch	D mm	X mm	G mm	t mm	B1 mm	T1 mm	A mm
1/2	89	30.2	35.1	11.2	15.7	47.8	21.3
3/4	99	38.1	42.9	12.7	20.8	52.3	26.7
1	108	49.3	50.8	14.2	26.7	55.6	33.5
1¼	117	58.7	63.5	15.7	35.1	57.2	42.2
1½	127	65.0	73.2	17.5	40.9	62.0	48.3
2	152	77.7	91.9	19.1	52.6	63.5	60.5
2½	178	90.4	104.6	22.4	62.7	69.9	73.2
3	191	108.0	127.0	23.9	78.0	69.9	88.9
3½	216	122.2	139.7	23.9	90.2	71.4	101.6
4	229	134.9	157.2	23.9	102.4	76.2	114.3
5	254	163.6	185.7	23.9	128.3	88.9	141.2
6	279	192.0	215.9	25.4	154.2	88.9	168.4
8	343	246.1	269.7	28.4	202.7	101.6	218.2
10	406	304.8	323.9	30.2	254.5	101.6	273.1
12	483	365.3	381.0	31.8	304.8	114.3	323.9
14	533	400.1	412.8	35.1	336.6	127.0	355.6
16	597	457.2	469.9	36.6	387.4	127.0	406.4
18	635	505.0	533.4	39.6	438.2	139.7	457.2
20	699	558.8	584.2	42.9	489.0	144.5	508.0
24	813	663.4	692.2	47.8	590.6	152.4	609.6

Size	Bolt Drilling			Bolting Requirements
inch	Bolt circle Diameter mm	Holes #	Holes Dia. mm	Bolt Dia. inch.	Length FF Flange	Length RF Flange	Length RTJ Flange
1/2	60.5	4	15.7	1/2	50.8	57.2	–
3/4	69.9	4	15.7	1/2	50.8	63.5	–
1	79.2	4	15.7	1/2	57.2	63.5	76.2
1¼	88.9	4	15.7	1/2	57.2	69.9	82.6
1½	98.6	4	15.7	1/2	63.5	69.9	82.6
2	120.7	4	19.1	5/8	69.9	82.6	95.3
2½	139.7	4	19.1	5/8	76.2	88.9	101.6
3	152.4	4	19.1	5/8	76.2	88.9	101.6
3½	177.8	8	19.1	5/8	76.2	88.9	101.6
4	190.5	8	19.1	5/8	76.2	88.9	101.6
5	215.9	8	22.4	3/4	82.6	95.3	108.0
6	241.3	8	22.4	3/4	82.6	101.6	114.3
8	298.5	8	22.4	3/4	88.9	108.0	120.7
10	362.0	12	25.4	7/8	101.6	114.3	127.0
12	431.8	12	25.4	7/8	101.6	120.7	133.4
14	476.3	12	28.4	1	114.3	133.4	146.1
16	539.8	16	28.4	1	114.3	133.4	146.1
18	577.9	16	31.8	1^1/8	127.0	146.1	158.8
20	635.0	20	31.8	1^1/8	139.7	158.8	171.5
24	749.3	20	35.1	1¼	152.4	171.5	184.2

WN CLASS 300

Weld neck flange dimensions class 300 (ASME B16.5) in millimeters

Size inch	D mm	X mm	G mm	t mm	B1 mm	T1 mm	A mm
1/2	95	38.1	35.1	14.2	15.7	52.3	21.3
3/4	117	47.8	42.9	15.7	20.8	57.2	26.7
1	124	53.8	50.8	17.5	26.7	62.0	33.5
1¼	133	63.5	63.5	19.1	35.1	65.0	42.2
1½	155	69.9	73.2	20.6	40.9	68.3	48.3
2	165	84.1	91.9	22.4	52.6	69.9	60.5
2½	191	100.1	104.6	25.4	62.7	76.2	73.2
3	210	117.3	127.0	28.4	78.0	79.2	88.9
3½	229	133.4	139.7	30.2	90.2	81.0	101.6
4	254	146.1	157.2	31.8	102.4	85.9	114.3
5	279	177.8	185.7	35.1	128.3	98.6	141.2
6	318	206.2	215.9	36.6	154.2	98.6	168.4
8	381	260.4	269.7	41.1	202.7	111.3	219.2
10	445	320.5	323.9	47.8	254.5	117.3	273.1
12	521	374.7	381.0	50.8	304.8	130.0	323.9
14	584	425.5	412.8	63.8	336.6	142.7	355.6
16	648	482.6	469.9	57.2	387.4	146.1	406.4
18	711	533.4	533.4	60.5	438.2	158.8	457.2
20	775	587.2	584.2	63.5	489.0	162.1	508.0
24	914	701.5	692.2	69.9	590.6	168.1	609.6

Size	Bolt Drilling			Bolting Requirements
inch	Bolt circle Diameter mm	Holes #	Holes Dia. mm	Bolt Dia. inch.	Length FF Flange	Length RF Flange	Length RTJ Flange
1/2	66.5	4	15.7	1/2	57.2	63.5	76.2
3/4	82.6	4	19.1	5/8	63.5	76.2	88.9
1	88.9	4	19.1	5/8	63.5	76.2	88.9
1¼	98.6	4	19.1	5/8	69.9	82.6	95.3
1½	114.3	4	22.4	3/4	76.2	88.9	101.6
2	127.0	8	19.1	5/8	76.2	88.9	101.6
2½	149.4	8	22.4	3/4	82.6	101.6	114.3
3	168.1	8	22.4	3/4	88.9	108.0	120.7
3½	184.2	8	22.4	3/4	95.3	108.0	127.0
4	200.2	8	22.4	3/4	95.3	114.3	127.0
5	235.0	8	22.4	3/4	108.0	120.7	133.4
6	269.7	12	22.4	3/4	108.0	120.7	139.7
8	330.2	12	25.4	7/8	120.7	139.7	152.4
10	387.4	16	28.4	1	139.7	158.8	171.5
12	450.9	16	31.8	1^1/8	146.1	171.5	184.2
14	514.4	20	31.8	1^1/8	158.8	177.8	190.5
16	571.5	20	35.1	1¼	165.1	190.5	203.2
18	628.7	24	35.1	1¼	171.5	196.9	209.6
20	685.8	24	35.1	1¼	184.2	203.2	222.3
24	812.8	24	41.1	1½	203.2	228.6	254.0

WN CLASS 600

Weld neck flange dimensions class 300 (ASME B16.5) in millimeters

Size inch	D mm	X mm	G mm	t mm	B1 mm	T1 mm	A mm
1/2	95	38.1	35.1	14.2	B36.10/.19	52.3	21.3
3/4	117	47.8	42.9	15.7	B36.10/.19	57.2	26.7
1	124	53.8	50.8	17.5	B36.10/.19	62.0	33.5
1¼	133	63.5	63.5	20.6	B36.10/.19	66.5	42.2
1½	155	69.9	73.2	22.4	B36.10/.19	69.9	48.3
2	165	84.1	91.9	25.4	B36.10/.19	73.2	60.5
2½	191	100.1	104.6	28.4	B36.10/.19	79.2	73.2
3	210	117.3	127.0	31.8	B36.10/.19	82.6	88.9
3½	229	133.4	139.7	35.1	B36.10/.19	85.9	101.6
4	273	152.4	157.2	38.1	B36.10/.19	101.6	114.3
5	330	189.0	185.7	44.5	B36.10/.19	114.3	141.2
6	356	222.3	215.9	47.8	B36.10/.19	117.3	168.4
8	419	273.1	269.7	55.6	B36.10/.19	133.4	219.2
10	508	342.9	323.9	63.5	B36.10/.19	152.4	273.1
12	559	400.1	381.0	66.5	B36.10/.19	155.4	323.9
14	603	431.8	412.8	69.9	B36.10/.19	165.1	355.6
16	686	495.3	469.9	76.2	B36.10/.19	177.8	406.4
18	743	546.1	533.4	82.6	B36.10/.19	184.2	457.2
20	813	609.6	584.2	88.9	B36.10/.19	190.5	508.0
24	940	717.6	692.2	101.6	B36.10/.19	203.2	609.6

Size	Bolt Drilling			Bolting Requirements
inch	Bolt circle Diameter mm	Holes #	Holes Dia. mm	Bolt Dia. inch.	Length FF Flange	Length RF Flange	Length RTJ Flange
1/2	66.5	4	15.7	1/2	76.2	69.9	76.2
3/4	82.6	4	19.1	5/8	88.9	82.6	88.9
1	88.9	4	19.1	5/8	88.9	82.6	88.9
1¼	98.6	4	19.1	5/8	95.3	88.9	95.3
1½	114.3	4	22.4	3/4	108.0	101.6	108.0
2	127.0	8	19.1	5/8	108.0	101.6	108.0
2½	149.4	8	22.4	3/4	120.7	114.3	120.7
3	168.1	8	22.4	3/4	127.0	120.7	127.0
3½	184.2	8	25.4	7/8	139.7	133.4	139.7
4	215.9	8	25.4	7/8	146.1	139.7	146.1
5	266.7	8	28.4	1	165.1	158.8	165.1
6	292.1	12	28.4	1	171.5	165.1	171.5
8	349.3	12	31.8	1^1/8	190.5	184.2	196.9
10	431.8	16	35.1	1¼	215.9	209.6	215.9
12	489.0	20	35.1	1¼	222.3	215.9	222.3
14	527.1	20	38.1	1^3/8	235.0	228.6	235.0
16	603.3	20	41.1	1½	254.0	247.7	254.0
18	654.1	20	44.5	1^5/8	273.1	266.7	273.1
20	723.9	24	44.5	1^5/8	285.8	279.4	292.1
24	838.2	24	50.8	1^7/8	330.2	323.9	336.6

WN CLASS 900

Weld neck flange dimensions class 300 (ASME B16.5) in millimeters

Size inch	D mm	X mm	G mm	t mm	B1 mm	T1 mm	A mm
1/2	121	38.1	35.1	22.4	B36.10/.19	60.5	21.3
3/4	130	44.5	42.9	25.4	B36.10/.19	69.9	26.7
1	149	52.3	50.8	28.4	B36.10/.19	73.2	33.5
1¼	159	63.5	63.5	28.4	B36.10/.19	73.2	42.2
1½	178	69.9	73.2	31.8	B36.10/.19	82.6	48.3
2	216	104.6	91.9	38.1	B36.10/.19	101.6	60.5
2½	244	124.0	104.6	41.1	B36.10/.19	104.6	73.2
3	241	127.0	127.0	38.1	B36.10/.19	101.6	88.9
4	292	158.8	157.2	44.5	B36.10/.19	114.3	114.3
5	349	190.5	185.7	50.8	B36.10/.19	127.0	141.2
6	381	235.0	215.9	55.6	B36.10/.19	139.7	168.4
8	470	298.5	269.7	63.5	B36.10/.19	162.1	219.2
10	546	368.3	323.9	69.9	B36.10/.19	184.2	273.1
12	610	419.1	381.0	79.2	B36.10/.19	200.2	323.9
14	641	450.9	412.8	85.9	B36.10/.19	212.9	355.6
16	705	508.0	469.9	88.9	B36.10/.19	215.9	406.4
18	787	565.2	533.4	101.6	B36.10/.19	228.6	457.2
20	857	622.3	584.2	108.0	B36.10/.19	247.7	508.0
24	1041	749.3	692.2	139.7	B36.10/.19	292.1	609.6

Size	Bolt Drilling			Bolting Requirements
inch	Bolt circle Diameter mm	Holes #	Holes Dia. mm	Bolt Dia. inch.	Length FF Flange	Length RF Flange	Length RTJ Flange
1/2	82.6	4	22.4	3/4	108.0	101.6	108.0
3/4	88.9	4	22.4	3/4	114.3	108.0	114.3
1	101.6	4	25.4	7/8	127.0	120.7	127.0
1¼	111.3	4	25.4	7/8	127.0	120.7	127.0
1½	124.0	4	28.4	1	139.7	133.4	139.7
2	165.1	8	25.4	7/8	146.1	139.7	146.1
2½	190.5	8	28.4	1	158.8	152.4	158.8
3	190.5	8	25.4	7/8	146.1	139.7	146.1
4	235.0	8	31.8	1^1/8	171.5	165.1	171.5
5	279.4	8	35.1	1¼	190.5	184.2	190.5
6	317.5	12	31.8	1^1/8	190.5	184.2	196.9
8	393.7	12	38.1	1^3/8	222.3	215.9	222.3
10	469.9	16	38.1	1^3/8	235.0	228.6	235.0
12	533.4	20	38.1	1^3/8	254.0	247.7	254.0
14	558.8	20	41.1	1½	273.1	266.7	292.1
16	616.0	20	44.5	1^5/8	285.8	279.4	298.5
18	685.8	20	50.8	1^7/8	323.9	317.5	333.6
20	749.3	20	53.8	2	349.3	342.9	362.0
24	901.7	20	66.5	1½	438.2	431.8	457.2

DIMENSIONAL TOLERANCE WELDING NECK FLANGE

Certificate	Plate thickness in mm	Width in mm	Length in mm
Outside Diameter	When O is 24″ or less. When O is over 24″.	±0.06″ ±0.12″	±1.6 mm	±3.2 mm
Diameter of Contact Face	0.06″ (1.6 mm) raised face. 0.25″ (6.4 mm) raised face.	±0.03″ ±0.02″	±0.8 mm	±0.5mm
Diameter of Hub at Point of Welding	NPS 5 and smaller. NPS 6 and larger.	+0.09″, -0.03″ +0.16″, -0.03″	+2.4 mm, -0.8mm	+4.0 mm, -0.8 mm
Inside Diameter	NPS 10, 12, 18, 20 and larger.	+0.03″ +0.06″ +0.12″, -0.06″	+0.8 mm +1.6 mm	+3.2 mm, -1.6 mm
Diameter of Hub at Base	Hub Base is 24″or less. Hub Base is over 24″.	+0.06″ +0.12″	+1.6 mm	+3.2 mm
Thickness	NPS 18 and smaller. NPS 20 and larger.	+0.12″ +0.19″	+3.2 mm	+4.8 mm
Drilling and Facings	Bolt circle diameter Bolt Hole Spacing	±0.06″ ±0.03″	±1.6 mm	±0.8 mm
Eccentricity of Bolt Circle and Facing	NPS 2 1/2 and smaller. NPS 3 and larger.	±0.03″ ±0.06″	±0.8 mm	±1.6 mm
Length Through Hub	NPS 10 and smaller. NPS 12 and larger.	±0.06″ ±0.12″	±1.6 mm	±3.2 mm

WN FLANGE WEIGHTS

WN FLANGE WEIGHT in KGS.

The table shows the ASME B16.5 welding-neck flange weights in Kgs. by Flange NPS and Class (carbon/alloy steel materials; for higher grades, consider adjusting weight using the delta-specific weight carbon/other grades)

NPS	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
1/2	0.9	0.9	1.4	1.4	3.2	3.2	3.6
3/4	0.9	1.4	1.6	1.8	3.2	3.2	4.1
1	1.4	1.8	1.8	1.8	3.8	4.1	5.9
1¼	1.4	2.3	2	2.7	4.5	4.5	9
1½	1.8	3.2	3.6	3.6	6.3	6.3	12.6
2	2.7	4.1	4.5	5.4	10.8	11.3	18.9
2½	4.5	5.4	6.3	8.1	13.9	16.2	23.4
3	5.2	8.1	8.1	10.4	16.2	21.6	42.3
3½	5.4	9	11.7	11.7	–
4	7.4	11.9	15.8	18.9	23.9	32.9	65.7
5	9.5	16.2	19.4	30.6	38.7	59.4	109.8
6	11.7	20.3	25.7	36.5	49.5	74.3	170.1
8	18.9	31.1	40.1	54	84.2	123.8	259.2
10	24.3	45	56.3	85.5	120.6	204.8	480.6
12	39.6	63.9	78.8	101.7	167.4	310.5	723.6
14	51.3	92.7	104.9	156.2	252.9	423
16	63	112.5	132.8	216.5	308.3	562.5
18	74.3	144	162	249.8	415.8	731.3
20	88.7	180	200.3	310.5	523.8	922.5
22	101.3	209.3	227.3	324	–	–
24	120.6	261	288	439.7	948.2	1496

WN FLANGE WEIGHT in LBS.

The table shows the ASME B16.5 weld-neck flange weights in Lbs. by Flange NPS and Class (carbon/alloy steel materials; for higher grades, consider adjusting weight using the delta-specific weight carbon/other grades)

CLASS 150	Nominal Pipe Size	Weld Neck Weight in Lbs./unit
	½	2
	¾	2
	1	3
	1¼	3
	1½	4
	2	6
	2½	10
	3	11.5
	3½	12
	4	16.5
	5	21
	6	26
	8	42
	10	54
	12	88
	14	114
	16	140
	18	165
	20	197
	22	225
	24	268
CLASS 300	Nominal Pipe Size	Weld Neck Weight in Lbs./unit
	½	2
	¾	3
	1	4
	1¼	5
	1½	7
	2	9
	2½	12
	3	18
	3½	20
	4	26.5
	5	36
	6	45
	8	69
	10	100
	12	142
	14	206
	16	250
	18	320
	20	400
	22	465
	24	580
CLASS 400	Nominal Pipe Size	Weld Neck Weight in Lbs./unit
	½	3
	¾	3.5
	1	4
	1¼	4.5
	1½	8
	2	10
	2½	14
	3	18
	3½	26
	4	35
	5	43
	6	57
	8	89
	10	125
	12	175
	14	233
	16	295
	18	360
	20	445
	22	505
	24	640
CLASS 600	Nominal Pipe Size	Weld Neck Weight in Lbs./unit
	½	3
	¾	4
	1	4
	1¼	6
	1½	8
	2	12
	2½	18
	3	23
	3½	26
	4	42
	5	68
	6	81
	8	120
	10	190
	12	226
	14	347
	16	481
	18	555
	20	690
	22	720
	24	977
CLASS 900	Nominal Pipe Size	Weld Neck Weight in Lbs./unit
	½	7
	¾	7
	1	8.5
	1¼	10
	1½	14
	2	24
	2½	31
	3	36
	4	53
	5	86
	6	110
	8	187
	10	268
	12	372
	14	562
	16	685
	18	924
	20	1164
	24	2107
CLASS 1500	Nominal Pipe Size	Weld Neck Weight in Lbs./unit
	½	7
	¾	7
	1	9
	1¼	10
	1½	14
	2	25
	2½	36
	3	48
	4	73
	5	132
	6	165
	8	275
	10	455
	12	690
	14	940
	16	1250
	18	1625
	20	2050
	24	3325
CLASS 2500	Nominal Pipe Size	Weld Neck Weight in Lbs./unit
	½	8
	¾	9
	1	13
	1¼	20
	1½	28
	2	42
	2½	52
	3	94
	4	146
	5	244
	6	378
	8	576
	10	1068
	12	1608

**DISCLAIMER: Accuracy and Reliability of Content**

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Projectmaterials Team

Blog.projectmaterials.com is an online resource dedicated to providing in-depth information, analysis, and educational content related to the fields of project materials management, engineering, and procurement, particularly within the oil & gas, construction, shipbuilding, energy, and renewable energy sectors. It aims to serve professionals and enthusiasts in these industries by offering valuable insights into materials, equipment, and techniques used in various projects, focusing on the selection, application, and maintenance of these resources. Key features of the blog include: * Educational Articles: Comprehensive posts that cover topics ranging from the technical aspects of piping products (pipes, valves, fittings, flanges, gaskets, bolts, instrumentation) to structural steel and process equipment (including oil extraction systems, drilling rigs, wellheads, pumps, compressors, and separation systems). * Industry Insights: Updates on the latest trends, technologies, and regulatory changes affecting the industries covered. * Guides and How-Tos: Practical advice on selecting the right materials and equipment for specific applications, as well as tips on installation, maintenance, and troubleshooting. * Safety and Standards: Information on safety equipment for production sites, risk mitigation procedures, and an overview of relevant industry standards and regulatory frameworks. The website is designed to support the professional development of engineers, procurement specialists, project managers, and other stakeholders involved in project plant businesses, by disseminating critical know-how and best practices. Whether readers are new to the field or seasoned professionals, blog.projectmaterials.com offers resources to enhance their understanding and performance in managing project materials effectively.

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4 Responses

Mohammed Khalid says:

January 16, 2024 at 7:52 pm

Hi
Please I would like file pdf of neck flange dimensions table

Reply
1. Projectmaterials says:
  
  March 11, 2024 at 12:31 pm
  
  Dear Mohammed Khalid,
  
  Thank you for your comment. We appreciate your interest in obtaining the PDF file of the neck flange dimensions table. Unfortunately, as mentioned in our previous conversation, we don’t have the capability to directly share files or provide downloads on this platform.
  
  However, we highly recommend visiting our website or conducting a quick internet search for the specific neck flange dimensions table you are looking for. Many manufacturers and suppliers offer comprehensive tables in PDF format that can be easily downloaded from their websites.
  
  By utilizing these resources, you should be able to find the exact information you need regarding weld neck flange dimensions in various classes such as 150, 300, 900, 1500, and 2500.
  
  We hope this helps, and please feel free to reach out if you have any further questions or require additional assistance.
  
  Best regards,
  
  Reply
jayanti mehta says:

May 1, 2023 at 11:25 am

REQUEST FOR YOUR REQUIREMENT FOR STAINLESS STEEL, CARBON STEEL, ALLOY STEEL, COPPER ALLOYS & EXOTIC NICKEL ALLOYS IN FORM OF PIPE, TUBE, SHEET, PLATES, FITTINGS & FLANGES We STELCO INOX INC are Fastest growing International Suppliers & Exporters of Industrial Raw material to world renowned companies in India & abroad, providing them with world class quality material and service. Our products are supplied & accepted by our clients in various sphere of industries ranging from basic industries such as Paper, Textile, Sugar, Dairy, Cement, Engineering to more complex such as Petroleum, Chemicals, Power, Offshore, Onshore & Nuclear Industries.

We have dedicated sources, expertise & full technical know-how to supply quality products as per Client’s basic & special requirements.

We deal in Stainless Steel, Carbon Steel, Alloy Steel, Copper Alloys & Exotic Nickel Alloys in form of Pipe, Tube, Sheet, Plates, Fittings & Flanges. We can fulfill Client’s requirement of all size as we stock huge amount of material from both indigenous & foreign manufactures.

Our major advantage is our qualified workforce, we have pool of specialist in field of Technical, Sales & Logistic, who are fully committed to provide with best solution for your business & can help you solve all your procurement problems.

At STELCO INOX INC Quality is Guaranteed, we take use of innovative & latest available technology to meet client’s full requirements regarding Quality & Value for money.

We hope the information provide on our site to be useful to you & you will forward us your regular enquiry and requirements & provide us with an opportunity to work with your esteem Organisation. If you have any suggestion or query, how we can serve you better please do inform us. your suggestion are heartily welcomed. Thank you and assuring you our best co-operation always. Thank you and Warm Regards, Jayanti K. Metha+91 922 22 44 084 GST No : 27BBHPM2810H1ZTSTELCO INOX INCOffice No.29, Plot No.156,2nd Floor,1,Callian Building ,Khadilkar Road,Kandewadi,Girgaon,Mumbai-400004T : +91 92222 44084 / 2381 2828W : www.stelcoinox.comE : stelcoinox@gmail.com

Reply
Murat Niksic says:

June 15, 2022 at 10:47 pm

There are mistake on the drawings and tables for metric units for threaded and WN flanges rated class 600 & 900 (other types were not checked).
Note that the RF (raised face dimension is not always 1.6 mm. For these flanges the height of raised face is 6.4 mm (0.25″). Also that height is not included in the overall length (or height) of the flange.

Reply

Welding Neck Flanges Dimensions & Weights (ASME B16.5)

Welding Neck Flanges Dimensions & Weights (ASME B16.5)

ASME WELDING NECK FLANGE DIMENSIONS & WEIGHTS

WN FLANGE SIZES IN INCHES

WN CLASS 150

WN CLASS 300

WN CLASS 400

WN CLASS 600

WN CLASS 900

WN CLASS 1500

WN CLASS 2500

WN FLANGE SIZES IN MILLIMETERS

WN CLASS 150

WN CLASS 300

WN CLASS 600

WN CLASS 900

DIMENSIONAL TOLERANCE WELDING NECK FLANGE

WN FLANGE WEIGHTS

WN FLANGE WEIGHT in KGS.

WN FLANGE WEIGHT in LBS.

Projectmaterials Team

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