Products  >>  Flanges  >>  Flange Tolerances Flange Tolerances   OUTSIDE DIAMETER ***     HUB         When O.D. is 24" or less------------------------ ± .06"   Welding Neck     When O.D. is over 24"---------------------------- ± .12"   Outside Diameter of hub at point of Weld           INSIDE DIAMETER   5" and smaller------------------------------------- + .09" - .03"         Slip-On, Lap Joint   6" and larger-------------------------------------- + .16" - .03"         10" and smaller------------------------------------- + .03" - .0"   Long Welding Neck ( O.D. of Neck )     12" to 24"-------------------------------------------- + .06" - .0"   10" and smaller---------------------------------- + .09" - .03"   26" and larger---------------------------------------- + .12" - .06"   12" and larger------------------------------------ + .09" - .06"         Welding Neck, Long Welding Neck   DRILLING         10" and smaller------------------------------------- ± .03"   Bolt Circle Diameter---------------------------- ± .06"   12" to 18"-------------------------------------------- ± .06"   Bolt Hole Spacing------------------------------- ± .03"   20" and larger--------------------------------------- + .12" - .06"   Concentricity of Bolt Circle and Facing ≥ 2 1/2" ± .03" ≤ 3" ± .06"         DIAMETER OF CONTACT FACE   OVERALL HEIGHT         1/16" Raised Face--------------------------------- ± .03"   Threaded, Slip-On, Lap Joint     1/4" Raised Face, Tongue and Groove,   All Sizes-------------------------------------------- ± .06"   Male or Female------------------------------------- ± .02"   Welding Neck           DIAMETER OF COUNTERBORE   4" and smaller------------------------------------ ± .06"         Threaded   5" to 10"-------------------------------------------- + .06" - .12"         10" and smaller------------------------------------- + .03" - .0"   12" and larger------------------------------------ + .12" - .18"   12" and larger--------------------------------------- + .06" - .0"             Socket Weld   DEPTH OF SOCKET WELD***         3" and smaller-------------------------------------- ± .01"   All Sizes-------------------------------------------- + .03" - .0"         FLANGE THICKNESS   Thickness of Hub at Point of Weld Not less than 87½ % of the nominal thickness of the pipe to which the flange is to be attached.       18" and smaller------------------------------------- + .12" - .0"     Over 18"----------------------------------------------- + .19" - .0"                   FACINGS   150 # and 300# Standard 400#, 600#, 900#, 1500# and 2500# Standard       1/16" raised face is standard and is INCLUDED in the flange 1/4" raised face is standard and is ADDED to the flange   thickness thickness                 *** Not covered by B16.5, added for completeness Dimensional Data Class 150 Class 300 Class 400 Class 600 Class 900 Class 1500 Class 2500 B16.47 Series A Class 150 Series A Class 300 Series A Class 400 Series A Class 600 Series A Class 900 Series B Class 150 Series B Class 300 Series B Class 400 Series B Class 600 Series B Class 900 Pipe Dimensions Flange Tolerances