Dimensions in Inches Weld Neck Flanges & Stud Bolts
according to ASME B16.5
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Weld Neck flange

Important  Information

Class  150 | 300 | 400 | 600 | 900 | 1500 | 2500

NPSDIA
D
THK
B
DIA
A
DIA
OD
HEIGHT
H
DIA
K
DIA
L
1/23.50.381.190.841.812.385/8
3/43.880.441.51.0522.755/8
14.250.51.941.322.123.125/8
4.620.562.311.662.193.55/8
50.622.561.92.383.885/8
260.693.062.382.444.753/4
70.813.562.882.695.53/4
37.50.884.253.52.6963/4
8.50.884.8142.7573/4
490.885.314.52.947.53/4
5100.886.445.563.448.57/8
6110.947.566.633.449.57/8
813.51.069.698.633.9411.757/8
10161.121210.753.9414.251
12191.1914.3812.754.44171
14211.3115.75144.9418.751.1/8
1623.51.3818164.9421.251.1/8
18251.519.88185.4422.75
2027.51.6222205.6225
24321.8126.12245.9429.51.3/8
Weld Neck flange
NPSNO OF
BOLT
HOLES
DIA
STUD
BOLTS
LENGTH
STUD
BOLTS
1/241/22.25
3/441/22.5
141/22.5
41/22.75
41/22.75
245/83.25
45/83.5
345/83.5
85/83.5
485/83.5
583/43.75
683/44
883/44.25
10127/84.5
12127/84.75
141215.25
161615.25
18161.1/85.75
20201.1/86.25
24206.75

Notes:

  • Dimensions are in inches unless otherwise indicated.
  • The length of the Stud Bolt does not include the height of the chamfers (points).
  • ID = Depending on the wall thickness of the pipe, must be specified by the purchaser.
Measuring lengths of Stud Bolts and Hex bolts
Dimensional Tolerances of Weld Neck Flanges ASME B16.5
Outside Diameter (Note 1)
≤24
0.06 in (1.6 mm)
>24
±0.12 in (±3.2 mm)
Diameter Hub at Base
≤24
0.06 in (1.6 mm)
>24
±0.12 in (±3.2 mm)
Inside Diameter
≤10
±0.03 in (±0.8 mm)
12 thru 18
0.06 in (1.6 mm)
≥20
±0.12 in / -0.06 in
(+3.2 mm / -1.6 mm)
Diameter Hub at Point of Welding
≤5
±0.09 in / -0.03 in
(+2.4 mm / -0.8 mm)
≥6
+0.15 in / -0.03 in
(+4.0 mm / -0.8 mm)

Drilling
Bolt Circle
0.06 in (1.6 mm)
Bolt Hole Spacing
±0.03 in (±0.8 mm)
Eccentricity Bolt Circle
≤2½
0.03 in max (0.8 mm max)
≥3
0.06 in max (1.6 mm max)
Thickness
≤18
+0.12 in / -0 (+3.2 mm / -0)
≥20
+0.18 in / -0 (+4.8 mm / -0)
Length thru Hub
≤10
0.06 in (1.6 mm)
≥12
±0.12 in (±3.2 mm)
Diameter Contact Face
0.06 in RF (1.6 mm)
±0.03 in (±0.8 mm)
0.25 in RF (6.35 mm)
±0.01 in (±0.4 mm)

Tongue & Groove
±0.01 in (±0.4 mm)
Male-Female
±0.01 in (±0.4 mm)
Welding bevel

0.03 in (1 mm)
0.07 in (2 mm)
0.23 in (6 mm)

(NOTE 1)
Tolerances not listed in
ASME B16.52013