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Precision Tube Standard

Steelforce_Precision Tube

Chemical composition

The carbon equivalent (CE) is determined in accordance with the equation from

AS 1450-2007, i.e.       CE = C + Mn/6 + (Cr + Mo + V)/5 + (Cu + Ni)/15

Full chemical analysis to be shown on Test Certificates.

Mechanical Properties

The mechanical tests – yield, tensile and elongation – will be carried out in accordance with AS1391. Prior to tensile testing, the test pieces shall be aged by heating to a temperature between 150°C and 200°C for not less than 15 min.
Elongation results shall be reported on a gauge length Lo = 5.65√So where So is the original cross-sectional area of the test piece before testing.
Test specimens are to be taken longitudinally from a major flat portion of the section.
Test frequency is as per AS 1450-2007.

Finish Coating

RHS and SHS – blue paint.
Pipe – black paint.
Pregal – zinc coated coil with Clearcote coating applied.

Coating Thickness

Painted product – minimum paint thickness of 9 microns
Pregal product – average zinc thickness of 50 grams per square metre per side (Z100).
– minimum Clearcote thickness of 9 microns.

Surface finish

Product shall be free from lamination, surface flaws and other defects detrimental to its use.

-0mm + 15mm (Standard lengths 6.5 and 8 metres)

End Condition

Products are supplied with mill cut ends with burr held to a minimum. End coding is applied in accordance with AS/NZS 4496:1997.

Straightness
The maximum permissible variation from straightness shall not exceed: – Specified length 500

Corner radius

Outside corner radius is 2 x gauge ± 0.5mm, i.e. 2t ± 0.5mm

Squareness of sides

Maximum permissible is 90o ± 1o

Twist

Maximum permissible is 2 mm + 0.5 mm/m length

External dimensions

RHS and SHS – ± 1%
CHS – + 0.1mm, – 0.3mm

Gauge

The maximum variation in thickness of all products will not exceed ± 10%.

Concavity/Convexity

Maximum 0.8% or 5mm, whichever is greater

Cold flattening test piece

The test piece shall be taken in the form of a cross-section from one end of a finished length of a circular tube which contains a longitudinal weld. The length of the test piece shall be not less than 40 mm. All burrs shall be removed before testing. The test piece shall be cut in the transverse direction.

Straightness

Profiles will be supplied to a straightness of Imm in 500mm measured as follows:-
The straightness will be calculated by measuring the horizontal deviation (a) over the ordered profile length (L), i.e. (a) L/500.

profile straightness

Corner radius

Corner radius is 2 times gauge plus or minus 0.5mm

Squareness

The maximum out of squareness of a profile will be plus or minus 1.5 degrees.

Twist

The maximum angle of twist of a profile (a) will be 1 degree in 1 metre.

profile twist

Flatness of sides

The flatness of any side (a) will be limited to less than 0.8% of the width of that side or 0.5mm, whichever is the greater.

flatness of sides

Dimensions

The maximum variation in leg and web dimensions of angles and channels will not exceed 1.5mm.
For the maximum variation in width of flats refer section 16 below.

Width of flats

The variation of the width (W) dimension of flats, where (t) is the designated thickness, are as
follows:-

profile width of sides

Gauge

The maximum variation in thickness of all profiles will not exceed plus or minus 10%.