Rolling tolerances to BS EN 10210-2: 2006 for Hot-Finished Square and Rectangular Hollow Sections

Designation	Property		Tolerance
	Depth or width D or B		±1.0% with a min of ±0.5 mm
	Thickness t	Welded	–10%
		Seamless	–10% but between 10% and 12.5% may occur over not more than 25% of the circumference
		Note: Positive deviation is limited by mass tolerance
	Squareness of side		90º ±1º
	External corner profile		3t max at each corner
	Concavity / convexity x		±1% of the side, measured independently of the tolerance on the outside dimension
Section is placed on a flat surface with one end held flat. At the other end the height difference of the two lower corners is taken	Twist v		2 mm plus 0.5 mm per m max
Measured at the centre of the length	Straightness (x or y direction)		0.20% L
Mass per unit length	Mass of section	Welded	±6.0% on individual lengths
Mass per unit length	Mass of section	Seamless	+8.0% -6% on individual lengths
Standard	Length L		+150 mm	–0 mm