Manufacturing tolerances may be specified to conform to ASTM — A 500 specification. Unless otherwise specified, all manufacturing tolerances will be suitable for standard structural applications.
Outside Dimensions (OD_{1}, OD_{2})
The specified dimensions, measured across the flats on rectangles and squares, at positions at least 2″ from either end and including an allowance for convexity or concavity, shall not exceed the plus and minus tolerances shown below.
Outside Dimensional Tolerances for Rectangular and Square Tubing 


Largest Outside Dimension Across Flats in Inches  Tolerance Plus or Minus 
Over 4 to 5″ 
040 
Chemical and Mechanical Properties
Chemical and mechanical properties of tubing shall conform to the properties of the starting material specified.
Corner Radius (R)
The outside corner radius of a rectangular or square section is generally 2 x’s the material thickness (t). Maximum tolerance 3t.
Wall Thickness (t)
The wall thickness at any point shall not exceed ± 12% of the nominal wall.
Squareness of Sides (X^{o})
Adjacent sides may deviate from 90o by a tolerance of ± 2o maximum.
Lengths
Cutting Tolerance



Exact Cut  Cut to size + – 0″ 
Min. R/L  Cut to min. size + 6″ (est.) – 0″ 
Random Lengths  15′ 24′, standard lengths 20′ 
Twist (T)
Maximum Twist
Specified Dimensions of Longest side, inches  

over 2″ to 4″ incl..075  6″ incl  over 4″ to 8″ incl.087 
over 6″ to.100  over 8″ .112 
Straightness (C)
The commercial tolerance for straightness is 1/8″ times the total number of feet of total length divided by 5.
125″ x total length 
5 
Largest Nominal Outside Dimension Across Flats, in. (mm) 
Wall Thickness inches. (mm)  ±, in. (mm), across Flats, Covexity or Concavity, incl 
To 11/4 (31.8), incl  all  0.015 (0.38) 
Over 114 to 21/2 (31.8 to 63.5) incl 
all  0.020 (0.51) 
Over 21/2 to 51/2 (63.5 to 139.7), incl  all  0.030 (0.76) 
Wall Thickness, in. (mm)  Radii of Corners max. in. (mm) 
Over 0.020 to 0.049 (0.51 to 1.24), incl. 
3/32 (2.4) 
Over 0.049 to 0.065 (1.24 to 1.65), incl  1/8 (3.2) 
Over 0.065 to 0.083 (1.65 to 2.11) , incl 
9/64 (3.6) 
Over 0.083 to 0.095 (2.11 to 2.42), incl  3/16 (4.8) 
Over 0.095 to 0.109 (2.42 to 2.77), incl 
13/64 (5.2) 
Over 0.109 to 0.134 (2.77 to 3.40), incl  7/32 (5.6) 
Over 0.134 to 0.156 (3.40 to 3.96), incl 
1/4 (6.4) 
Largest Size, in. (mm)  Twist in 3 ft.Max. in. (mm/m) 
Under 1/2 (12.7)  0.050 (1.4) 
1/2 to 11/2 (12.7 to 38.1), incl 
0.075 (2.1) 
Over 11/2 to 21/2 (38.1 to 63.5), incl  0.095 (2.6) 
Over 21/2 (63.5)  0.125 (3.5) 
±B = C x 0.006 where: B = tolerance for outofsquare, and C = length of longest side. The straightness tolerance is 0.075 in. in 3 ft. or 2.1 mm in 1 m using a 3 ft. (1m) straightedge and feeler gage. 
AWall tolerance is ± 10% of nominal wall thickness 
TOLERANCE GUIDELINES – 200K DRAWBENCH – [AS PER ASTM A 500]
Outside Dimensions
The specified dimensions, measured across the flats on rectangles and squares, at positions at least 2″ from either end and including an allowance for convexity or concavity, shall not exceed the plus and minus tolerances shown below . . .
Outside Dimensional Tolerances for Rectangular and Square Tubing 
Tolerance Plus or Minus  

Largest Outside DimensionalAcross Flats in Inches  
Over 31/2″ to 51/2″ incl
Over 51/2″ 
.030″ 1% 
Corner Radius — The outside corner radius of rectangular or square section is generally 2 times the material thickness. Maximum tolerance 3 times.
Wall Thickness — The wall thickness of any point shall not exceed ± 121/2%.
Squareness of Sides
Adjacent side may deviate from 90° by a tolerance of ± 2° maximum.
Twist
Maximum Twist Specified dimensions of longest side
over 21/2″ to 4″ incl.  over 4″ to 6″ incl.087″  over 6″ to 8″ incl .100″  over 8″ .100″ 
Straightness — The commercial tolerance for straightness is 1/8″ times the total number of feet of total length divided by 5.
DIAMETER,WALL,AND*
OVALITYTOLERANCES [AS PER ASTM A 554]
(All Conditions Except Tubing with Bead Removed)
Note 1 — Ovality is the difference between maximum and minimum outside diameters measured at any one cross section. There is no additional tolerance for ovality on tubes having a nominal wall thickness of more than 3% of the outside diameter.
Note 2 — For sizes up to and including 5in. (127.0mm) outside diameter, an ovality tolerance of twice the tubular outside diameter tolerance spread shown is applied one half plus and one half minus to tubes having a nominal wall thickness of 3% or less of the nominal outside diameter readings should fall within the outside diameter tolerances as shown in this table.
Note 3 — For sizes over 5in. (127.0mm) to and including 16in. (406.4 mm) outside diameter, when the specified wall thickness is 3% or less of the outside diameter, the ovality shall not exceed 1.5% of the specified outside diameter.
OD Size, In. (mm)  Wall Thickness  OD, ±  

in  mm  in  mm  
Under 1/2 (12.7) 
0.020 to 0.049  0.51 to 1.24 
0.004  0.10 
1/2 to 1 (12.7 to 25.4)  0.020 to 0.065  0.51 to 1.65  0.005  0.13 
1/2 to 1 (12.7 to 25.4)  over 0.065 to 0.134 
over 1.65 to 3.40  0.010  0.25 
Over 1 to 11/2 (25.4 to 38.1), incl. 
0.025 to 0.065  0.64 to 1.65 
0.008  0.20 
Over 1 to 11/2 (25.4 to 38.1), incl.  over 0.065 to 0.134 
over 1.65 to 3.40  0.010  0.25 
Over 11/2 to 2 (38.1 to 50.8), incl.  0.025 to 0.049  0.64 to 1.24  0.010  0.25 
Over 11/2 to 2 (38.1 to 50.8), incl. 
over 0.049 to 0.083 
over 1.24 to 2.11  0.011  0.28 
Over 11/2 to 2 (38.1 to 50.8), incl. 
over 0.083 to 0.149  over 2.11 to 3.78  0.012  0.30 
Over 2 to 21/2 (50.8 to 63.5), incl.  0.032 to 0.065  0.81 to 1.65  0.012  0.30 
Over 2 to 21/2 (50.8 to 63.5), incl.  over 0.065 to 0.109 
over 1.65 to 2.77  0.013  0.33 
Over 2 to 21/2 (50.8 to 63.5), incl. 
over 0.109 to 0.165 
over 2.77 to 4.19  0.014  0.36 
Over 21/2 to 31/2 (63.5 to 88.9), incl. 
0.032 to 0.165  0.81 to 4.19  0.014  0.36 
Over 21/2 to 31/2 (63.5 to 88.9), incl. 
over 0.165  over 4.19  0.020  0.51 
Over 31/2 to 5 (88.9 to 127.0), incl. 
0.035 to 0.165  .89 to 4.19  0.020  0.51 
Over 31/2 to 5 (88.9 to 127.0), incl.  over 0.165  over 4.19  0.025  0.64 
Over 5 to 16 (127.0 to 406.4), incl. 
all  all  0.00125 in./in. or mm/mm of circumference 
* Wall Tolerance ± 10% of nominal wall thickness