Flange Dimensional Tolerances
This table displays Flange Dimensional Tolerances by inside, outside, and contact diameter, thickness, and drilling tolerances for bolt holes diameter and spacing. These standard flange dimensional tolerances are ideal when other specifications aren’t used.
| OUTSIDE DIAMETER | When O.D. is 24" or less | +1/8", -1/16" |
| OUTSIDE DIAMETER | When O.D. is over 24" | +1/8", -1/8" |
| INSIDE DIAMETER | When I.D. is 10" and Smaller | +1/32",- 0" |
| INSIDE DIAMETER | When I.D. is over 10” | +1/16",- 0" |
| CONTACT FACE DIAMETER | 1/16" Raised Face And 1/4" Raised Face | +1/64",- 1/64" |
| DRILLING | Bolt Hole Diameter | +1/32”, -1/32” |
| DRILLING | Bolt Circle Diameter | + 1/16”, - 1/16" |
| DRILLING | Bolt Hole Spacing | + 1/32”, - 1/32" |
| THICKNESS | When nominal size is 18" and smaller | +1/8", -0" |
| THICKNESS | When nominal size is 20" and larger | +3/16",- 0" |