TUBING & PIPE

MECHANICAL TUBING TOLERANCES
Tolerances, Outside Dimensions
Square and Rectangular Tubing*
Widest Side
(inches)
Tolerance
(inches)
3/8 thru 5/8 Plus or Minus .004
Over 5/8 up to 1-1/8 Plus or Minus .005
1-1/8 up to 1-1/2 Plus or Minus .006
1-1/2 to 2 Plus or Minus .008
*Measured at corners at least 2" from cut end of tubing.
Convexity and Concavity Tolerances**
Widest Side
(inches)
Tolerance
(inches)
Up thru 2-1/2 Plus or Minus .010
Over 2-1/2 to 4 Plus or Minus .015
**Measured in center of the flat sides, applies to size determined at the corners.
Straightness Tolerances
Max. = 1/16" in 3'
STRUCTURAL TUBING TOLERANCES
Outside dimension tolerances for Square and Rectangular Structural
Tubing
Largest Outside Dimension,
Across Flats - inches (mm)
Tolerance*, Plus and Minus
inches (mm)
Up thru 2-1/2 (63.5) 0.020 (0.51)
Over 2-1/2 thru 3-1/2 (63.5 to 88.9) 0.025 (0.64)
Over 3-1/2 thru 5-1/2 (88.9 to 139.7) 0.030 (0.76)
Over 5-1/2 (139.7) ±1%
*Tolerances include allowance for convexity and concavity. For rectangular sections,
the tolerance calculated for the larger flat dimension shall also apply to the
smaller flat dimension. This tolerance may be increased 50% when applied to the
smaller dimension, if the ratio of cross-sectional dimensions is between 1.5 and 3,
and 100% when the ratio exceeds 3.
Specified Mill Length Tolerances for Square and
Rectangular Structural Tubing
Widest Side
(inches)
Up thru 22 ft. (6.7m)
Over
Under
Over 22 ft. thru 44 ft.
(6.7m thru 13.4m)
Over
Under
Length Tolerance
for Specified 1/2 1/4 3/4 1/4
Mill Length, (12.7) (6.4) (19.0) (6.4)
Inches (mm)
*Measured at corners at least 2" from cut end of tubing.
Straightness Tolerances
Max. = .025" per ft.
7-43