ASTM Specification & Tolerance For Tubing & Piping
Steel pipe tolerances and deviations
Deviation means that in the production process, due to the fact that the actual size is difficult to meet the nominal size requirements, that is often more or less than the nominal size, the standard allows a difference between the actual size and the nominal size. Positive values are called positive deviations, and negative values are called negative deviations.
Tolerance means that the sum of the absolute values of positive and negative deviations specified in the standard is called tolerance. The deviation is directional, ie, represented by "+" or "-"; the tolerance is not directional
Common stainless steel pipe standards for tolerances and deviations
ASTM A213/A213M Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes
ASTM A249/A249M Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes
ASTM A269/A269M Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service
ASTM A270/A270M Standard Specification for Seamless and Welded Austenitic and Ferritic/Austenitic Stainless Steel Sanitary Tubing
ASTM A312/A312M Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
ASTM A358/A358M Standard Specification for Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless Steel Pipe for High-Temperature Service and General Applications
ASTM Specification & Tolerance For Tubing & Piping
Standard |
Allowable Outside Diameter Variation in mm | Allowable Wall Thickness Variation | Exact Length Tolerance in mm | Testing | ||||
| Nominal Diameter | Over | Under | %Over | %Under | Over | Under | ||
ASTM-A213
|
Under 25.4 | .1016 | .1016 | +20 | -0 | 3.175 | 0 | Flattening Test |
| 25.4-38.1 incl | .1524 | .1524 | +22 | -0 | 3.175 | 0 | Tension Test | |
| 38.1-50.8 excl | .2032 | .2032 | +22 | -0 | 3.176 | 0 | Flare Test | |
| 50.8-63.5 excl | .254 | .254 | +2 | -0 | 4.46 | 0 | Hardness Test | |
| 63.5-76.2 excl | .3048 | .3048 | +22 | -0 | 4.76 | 0 | 100% Hydrostatic test | |
| 76.2-101.6 incl | .381 | .381 | +22 | -0 | 4.76 | 0 | Refer to ASTM A-450 | |
ASTM-A249
|
Under 25.4 | .1016 | .1016 | +10 | -10 | 3.175 | 0 | Tension Test |
| 25.4-38.1 incl | .1524 | .1524 | +10 | -10 | 3.175 | 0 | Flattening Test | |
| 38.1-50.8 Excl | .2032 | .2032 | +10 | -10 | 3.175 | 0 | Flange Test | |
| 50.0-63.5 excl | .254 | .254 | +10 | -10 | 4.762 | 0 | Reverse Bend Test | |
| 63.5-76.2 excl | .3848 | .3848 | +10 | -10 | 4.762 | 0 | Hardness Test | |
| 76.2-101.6 incl | .381 | .381 | +10 | -10 | 4.762 | 0 | 100% Hydrostastic Test Refer to ASTM A-450 | |
| Minimum Wall tubes +18% 0 available On request | ||||||||
ASTM-A269
|
Untp12.7 | .13 | .13 | +15 | -15 | 3.2 | 0 | Flare Test (Seamless Only) |
| 12.7-38.1 exc! | .13 | .13 | +10 | -10 | 3.2 | 0 | Flange Test (Welded Only) | |
| 38.1-88.9 excl | .25 | .25 | +10 | -10 | 4.8 | 0 | Hardness Test | |
| 88.9-139.7 excl | .38 | .38 | +10 | -10 | 4.8 | 0 | Reverse Flattening Test | |
| 139.7-203.2 excl | .76 | .76 | +10 | -10 | 4.8 | 0 |
(Welded only) 100% Hydrostatic Test Refer to ASTM-A269 |
|
ASTM-A270
|
25.4 | .05 | .20 | +10.0 | -10.0 | 3.2 | 0 | Reverse flattening Test |
| 38.1 | .05 | .20 | +10.0 | -10.0 | 3.2 | 0 | 100% Hydrostastic Test | |
| 50.8 | .05 | .28 | +10.0 | -10.0 | 3.2 | 0 | External' polish on all tubes | |
| 60.5 | .05 | .28 | +10.0 | -10.0 | 3.2 | 0 | Refer to ASTM A-270 | |
| 76.2 | .08 | .30 | +10.0 | -10.0 | 3.2 | 0 | ||
| 101.6 | .08 | .38 | +10.0 | -10.0 | 3.2 | 0 | ||
ASTM-A312
|
3.175-38.1 incl | .4 | .79 | Minimum Wall 12.5% under nominal wall Specified | 6.4 0 | 0 | Tension Test | |
| 38.1-1016 incl | .79 | .79 | 6.4 0 | 0 | Flattening Test | |||
| 101.6-203.2 imcl | 1.59 | .79 | 6.4 0 | 0 | 100% Hydrostatic Test | |||
| (Normally Random Lengths ordered | Refer to ASTM A-530 | |||||||
ASTM A-358
|
219.08-750mm or 0.01 inch | +0.5% | -0.3 | 6.0 | Refer to ASTM A-530 | |||
