Manufacturing Standards

All our products are quality accredited to ISO 9001 and compliant with applicable Australian and New Zealand Standards. Read more about our commitment to steel manufacturing standards here.

Hollow Sections – Standard Grades include: C250, C250L0, C350 * C350L0.

Pipe and Tube Tolerances

wdt_ID	Characteristic	Circular hollow sections hollow sections	Square & rectangular hollow sections
1	External Dimensions (d, b, do)	±1% minimum of ±0.5mm and maximum of ±10mm	Minimum of ±0.5mm
2	Thickness (t)	±10%	±10%
3	Out-of-roundness (o)	±2% for hollow sections having a diameter to thickness ratio not exceeding 100 (see note 1)	≤2mm + 0.5mm per meter length
4	Concavity/convexity (see note 2)	-	maximum 0.8% or 0.5mm whichever is greater
5	Squareness of sides	-	90 degrees ±1 degree
6	Corner Radius -	-	<50x50 1.5t to 3.0t
7			>50x50 1.8t to 3.0t
8	Twist (v)	-	≤2mm + 0.5mm per meter length
9	Straightness (a)	a ≤0.2% of total length (in mm)	a ≤0.15% of total length (in mm)
10	Length	-0mm +20mm	-0mm +20mm
11	Mass	no less than 0.96 x specified mass	no less than 0.96 x specified mass

Notes

Where the diameter to thickness exceeds 100, the tolerance on out-of-roundness becomes the subject of agreement between the manufacturer and purchaser.
The tolerance on concexity and concavity is independent of the tolerance on external dimensions.
The straighness tolerance applies to straightness in any one plane.
In lieu of any other requirement, the specified mass is considered to be the nominal mass.