Flange Tolerance

Flange Tolerance

Tolerance of Welding Neck Flanges
Outside Diameter When O.D. is 24″ or less  ±1.6mm﹡
Inside Diameter 10″ and smaller  ±0.8mm
12″ thru 18″  ±1.6mm
20″ and larger  +3.2mm, -1.6mm
Outside Diameter of hub 5″ and smaller  +2.4mm, -0.8mm﹡
6″ and larger  +4.0mm, -0.8mm
Diameter of contact face 1/16″ rasied face tongue and groove male, female  ±0.8mm
1/4″ rasied face tongue and groove male, female  ±0.4mm
Diameter of hub at base when hub base is 24″ or smaller  ±1.6mm﹡
Diameter of hub at point of welding 5″ and smaller  +2.4mm, -0.8mm
6″ and larger  +4.0mm, -0.8mm
Drilling Bolt circle  ±1.6mm
Bolt hole spacing  ±0.8mm
Eccentricity of bolt circle with respect to facing 2 1/2″ and smaller: 0.8mm, max﹡
Eccentricity of bolt circle with respect to bore 3″ and larger: 1.6mm, max﹡
Thickness 18″ and smaller  +3.2mm, -0mm
20″ and larger  +4.8mm, -0mm
Length of thru hub 10″ and smaller  ±1.6mm
12″ and larger  ±3.2mm
Tolerance of Threaded Flanges, Socket Welding Flanges, Slip-On Flanges
Lap Joint Flanges and Blind Flanges
Outside Diameter When O.D. is 24″ or less  ±1.6mm﹡
Inside Diameter Threaded Within limits on boring gauge
Socket welding, Slip-on and Lap joint, 10″ and smaller  +0.8mm, -0mm
Socket welding, Slip-on and Lap joint, 12″ and larger  +1.6mm, -0mm
Outside Diameter of hub 5″ and smaller  +2.4mm, -0.8mm﹡
6″ and larger  +4.0mm, -0.8mm
Diameter of contact face 1/16″ rasied face tongue and groove male, female  ±0.8mm
1/4″ rasied face tongue and groove male, female  ±0.4mm
Diameter of counterbore same as for inside diameter
Drilling Bolt circle ±1.6mm
Bolt hole spacing ±0.8mm
Eccentricity of bolt circle with respect to facing 2 1/2″ and smaller: 0.8mm, max﹡
Eccentricity of bolt circle with respect to bore 3″ and larger: 1.6mm, max﹡
Thickness 18″ and smaller  +3.2mm, -0mm
20″ and larger  +4.8mm, -0mm
Length of thru hub 10″ and smaller  ±1.6mm
12″ and larger  ±3.2mm

--- Hot flanges by Sunny Steel ---

  • Blind Flanges, BL Flange, BLRF
    The blind flange is used to close ends of piping systems.