CSA G40.21· Canada

350W

Canada's standard weldable structural grade: 350 MPa (50 ksi) yield, 450–650 MPa tensile.

Compared with S355 on its equivalents table.

Nominal thicknessmm

Yield strength ReH: ≥ 350MPa
Corroborated≤ 63.5 mm · up to 2½ in.
Tensile strength Rm: 450–655MPa
Corroborated
Elongation after fracture A: ≥ 19%
Single sourcelongitudinal, in 8 in.

All values

Strength

Yield strength ReH

Upper yield strength guaranteed by the product standard (minimum).

Condition	Value	Evidence
	≥ 350MPa	Corroborated
	≥ 317MPa	Single source

Tensile strength Rm

Ultimate tensile strength. Product standards give a range or a minimum.

Condition	Value	Evidence
	450–655MPa	Corroborated1

Ductility

Elongation after fracture A

Minimum elongation; depends on gauge length and test direction.

Condition	Value	Evidence
	≥ 19%	Single source

Chemical composition

Show on the periodic table

350W (50W), heat analysis, % by mass, maximum

Element	Applies to	Max %	Evidence
C	all thicknesses	0.23	Single source
Mn	all thicknesses	1.50	Single source
P	all thicknesses	0.040	Single source
S	all thicknesses	0.050	Single source
Si	all thicknesses	0.40	Single source

Listed as equivalent to

S355 (EN 10025-2:2019) — Yield 350 MPa (50 ksi), 5 MPa below S355, and only 46 ksi above 2½ in.; tensile 65–95 ksi. W has no guaranteed impact test; 350WT adds it.

Sources here are public pages that reproduce CSA G40.21. For design and acceptance, the standard edition named in your specification and the inspection certificate (EN 10204 3.1) of the delivered product take precedence.