Steel

S355 and every grade the world lists against it, compared on what each standard guarantees. Some “equivalents” fall short; their yield shows it.

Grade	Standard	Yield strength at 10 mm	Tensile strength	Closest to	Evidence
Grade 350 Australian and New Zealand plate grade: 360 MPa yield up to 12 mm, 450 MPa minimum tensile.	AS/NZS 3678:2016	≥ 360 MPa2	≥ 450 MPa2	S355Approximate	Corroborated 4 Single source 7

Galvanized and metallic-coated sheet, usually 0.4–3 mm, roll-formed into purlins, rails, studs, decking and cladding. Designed to EN 1993-1-3, AISI S100 or AS/NZS 4600. The full-hard grades (S550GD, G550, SS Grade 80) are strong but have almost no elongation.

Grade	Standard	Yield strength	Tensile strength	Closest to	Evidence
G300 Australian/NZ coated sheet for formed sections: 300 MPa yield, 340 MPa tensile, good ductility.	AS 1397	≥ 300 MPa1	≥ 340 MPa1		Single source 2
G550 Australian/NZ full-hard sheet for roofing and light framing: 550 MPa yield and tensile, 2 % elongation.	AS 1397	≥ 550 MPa1	≥ 550 MPa1	S550GDClose match	Single source 3