707.10 Square & Rectangular Tubing 
1. Specification:
707.10 C&MS.
2. Sampling and/or Inspection Requirements:
Materials considered as component part of guardrail items. Typically used for bridge railing and shipped, after fabrication, by TE24.
No sample required except for special uses. Acceptance for special uses can be through certified test data and TE30.
3. Methods of Tests:
707.10 C&MS
ASTM A 501 or A 500, Grade B with following modification: Galvanize tubing according to 711.02 C&MS.
4. Addendum:
Dimensions and Tolerances:
Tolerances permitted on square and rectangular steel tubing, ASTM A 500 and ASTM A 501:
Outside Dimension Tolerances for square, rectangular tubing:
Largest Outside Dimension Across Flats,  Tolerance,* plus and minus,  
in. (mm)  in.  (mm) 
2 ½ (63.5) and under  0.020  (0.51) 
over 2 ½ to 3 ½ (63.5 to 88.9), incl.  0.025  (0.64) 
over 3 ½ to 5 ½ (88.9 to 139.7), incl.  0.030  (0.76) 
over 5 ½ (139.7)  1 percent 
*The respective outside dimension tolerances include the allowances for convexity and concavity.
Straightness: Permissible variation shall be 1/8 in. times the number of feet of total length divided by 5.
Squareness of Sides: Adjacent sides may deviate from 90 degrees by a tolerance of ±2 degrees maximum.
Radius of Corners: Radius of any outside corner shall not exceed three times the specified wall thickness.
Twist Tolerances for Square and Rectangular Structural Tubing
Specified
Dimension of Longest Side, in. (mm) 
Maximum
Twist in the First 3 ft. (1 m) and in each addition 3 ft. 

In.  Mm  
1 ½ (38.1) and under  0.050  1.39 
Over 1 ½ to 2 ½ (38.1 to 63.5), incl.  0.062  1.72 
Over 2 ½ to 4 (63.5 to 101.6), incl.  0.075  2.09 
Over 4 to 6 (101.6 to 152.4), incl.  0.087  2.42 
Over 6 to 8 (152.4 to 203.2), incl.  0.100  2.78 
Over 8 (203)  0.112  3.11 
Twist: is measured by holding down one end of a square or rectangular tube on a flat surface plate with the bottom side of the tube parallel to the surface plate and noting the height that either corner, at the opposite end of the bottom side of the tube, extends above the surface plate. Difference in height of corners shall not exceed table values.
Wall Thickness: ASTM A 500 Tolerance (10%) of nominal wall thickness specified At center of flat, exclusive of weld area. ASTM A 501 not covered by tolerance. Calculated nominal wall thickness only item listed.
Weight per Foot: ASTM A 501 weight to be not less than 3.5% of the nominal value shown for standard tubing. ASTM A 500 not covered by tolerances.