Dimensional tolerance for ASTM A500 square tube:
1. External Dimensions: External dimensions shall be measured at least 2 inches (5 cm) from the pipe end and shall not differ from the required external dimensions by the appropriate values given in Table 3, including tolerances for concave and convex.
2. Wall Thickness: The minimum wall thickness measured at any point on the pipe cannot be less than 10% of the required wall thickness. The maximum wall thickness including the welds of the pipe shall not exceed 10% of the required wall thickness. ASTM A500 square tube wall thickness applies only to the center location.
3. Length: Structural pipes are usually produced in indefinite lengths of 5 feet (1.5 meters), multiple lengths and specified lengths. Refer to the table below
|Below 22 feet||Above 22 feet|
4. Straightness: Structural pipe flatness tolerance is 1/8 inch times total length divided by 5 feet (10 mm times meters).
5. Square surface: ASTM A500 square tube has each adjacent side at 90°, with a maximum allowable deviation of +2%.
6. Corner radius: The outer corner of each interface of the ASTM A500 square tube cannot exceed 3 times the required wall thickness.
7. Bending: The allowable tolerance of bending of ASTM A500 square tube is shown in the table below. The degree of curvature is determined by fixing one end of the tube on the flat plate and measuring the height of each corner of the bottom from the opposite end of the tube, and calculating the degree of curvature (the different heights of these corners), except that the degree of curvature can be determined by using some suitable measuring tools. . Bend testing cannot be done 2 inches (5 cm) from the pipe end.
Specified outside large flat dimension,in.(mm)
|Maximum permissible variations in twist per 3 ft of length (twist per metre of length)|
|Over 11/2 to 21/2(40 to 65),incl||0.062||(1.6)|
|Over 21/2 to 4(60 to 100),incl||0.075||(1.9)|
|Over 4 to 6(100 to 150),incl||0.087||(2.2)|
|Over 6 to 8(150 to 200),incl||0.100||(2.5)|
|Over 8 (200)||0.112||(2.8)|