European Steel fy/fu Tables — EN 10025-2 Yield and Tensile Strength

Q: What is the yield strength of S355 steel at 50 mm thickness?

S355 steel at 50 mm thickness falls in the 40 < t ≤ 63 mm bracket. Per EN 10025-2, the minimum yield strength is 335 MPa at this thickness range. The tensile strength remains 470-630 MPa.

Q: What is the difference between S235JR and S235J2 mechanical properties?

S235JR and S235J2 have identical yield strength (235 MPa for t ≤ 16 mm) and tensile strength (360-510 MPa for t ≤ 40 mm). The difference is in Charpy impact testing only: JR requires 27 J at 20°C, J2 requires 27 J at -20°C.

Q: What fu value should I use for bolt bearing resistance per EN 1993-1-8?

For bolt bearing resistance per EN 1993-1-8 Clause 3.6, use the ultimate tensile strength fu of the connected plate (not the bolt). For S355 steel, use fu = 470 MPa (minimum for t ≤ 40 mm). Include the partial factor γ_M2 = 1.25 in the resistance calculation.

Complete mechanical properties reference for European structural steels per EN 10025-2:2019. Yield strength (fy) and ultimate tensile strength (fu) for S235JR, S235J0, S235J2, S275JR, S275J0, S275J2, S355JR, S355J0, S355J2, S355K2, S420, and S460 grades with thickness-dependent reductions.

Quick access: European Steel Grades → | European Steel Properties → | European Beam Sizes →

Nominal Yield Strength fy by Thickness

EN 10025-2 defines yield strength that varies by product thickness. The nominal yield strength fy is the minimum specified value at the smallest thickness bracket.

Grade	t ≤ 16 mm fy	16 < t ≤ 40 mm fy	40 < t ≤ 63 mm fy	63 < t ≤ 80 mm fy	80 < t ≤ 100 mm fy	100 < t ≤ 150 mm fy
S235	235 MPa	225 MPa	215 MPa	215 MPa	215 MPa	195 MPa
S275	275 MPa	265 MPa	255 MPa	245 MPa	235 MPa	225 MPa
S355	355 MPa	345 MPa	335 MPa	325 MPa	315 MPa	295 MPa
S420	420 MPa	400 MPa	390 MPa	370 MPa	—	—
S460	460 MPa	440 MPa	430 MPa	410 MPa	—	—

Key observation: Yield strength reduces with increasing thickness. The reduction is approximately 15-20% from the thinnest to the thickest bracket depending on grade. For S355, fy drops from 355 MPa at t ≤ 16 mm to 295 MPa at 100 < t ≤ 150 mm, a 17% reduction.

Ultimate Tensile Strength fu by Thickness

S235 Series

Grade	t ≤ 40 mm fu	40 < t ≤ 63 mm fu	63 < t ≤ 100 mm fu	100 < t ≤ 150 mm fu
S235	360-510 MPa	360-510 MPa	350-500 MPa	350-500 MPa

S275 Series

Grade	t ≤ 40 mm fu	40 < t ≤ 63 mm fu	63 < t ≤ 100 mm fu	100 < t ≤ 150 mm fu
S275	370-530 MPa	370-530 MPa	360-520 MPa	350-510 MPa

S355 Series

Grade	t ≤ 40 mm fu	40 < t ≤ 63 mm fu	63 < t ≤ 100 mm fu	100 < t ≤ 150 mm fu
S355	470-630 MPa	470-630 MPa	450-610 MPa	440-600 MPa

S420 and S460 Series

Grade	t ≤ 40 mm fu	40 < t ≤ 63 mm fu	63 < t ≤ 100 mm fu
S420	520-680 MPa	520-680 MPa	500-660 MPa
S460	540-720 MPa	540-720 MPa	530-710 MPa

fy/fu Ratio and Ductility

EN 1993-1-1 Clause 3.2 specifies ductility requirements for structural steels. The fy/fu ratio and elongation must satisfy:

Parameter	EN 1993-1-1 Requirement	Typical S235	Typical S275	Typical S355	Typical S460
fu/fy ratio	≥ 1.10 (recommended)	1.35-1.55	1.35-1.55	1.30-1.45	1.15-1.30
Elongation at break	≥ 15% (recommended)	24-28%	22-26%	20-24%	17-22%
fy/E	—	0.00112	0.00131	0.00169	0.00219

The fu/fy ratio is important for:

Connections: EN 1993-1-8 requires fu for bolt bearing and weld design. Higher fu gives higher bearing resistance.
Plastic design: A minimum fy/fu ratio ensures strain-hardening capacity for moment redistribution.
Seismic design: Ductile frames require sufficient strain-hardening for plastic hinge formation.

Design Values per EN 1993-1-1

For EN 1993 design, use the following partial factors:

γ_M0 = 1.00 — Cross-section resistance
γ_M1 = 1.00 — Member buckling resistance
γ_M2 = 1.25 — Cross-section resistance in tension (net section), connection resistance

The design yield strength is fy_d = fy / γ_M0 for most limit states. For net section fracture at bolt holes, use fu / γ_M2.

International Grade Comparisons

European	AISC (US)	AS/NZS (Australia)	CSA G40.21 (Canada)
S235JR	A36	Grade 250	260W
S275JR	A572 Gr 42	Grade 300	300W
S355JR	A572 Gr 50	Grade 350	350W
S420JR	A572 Gr 60	Grade 400	400W
S460JR	A572 Gr 65	—	—

Note that A572 Grade 50 has fy = 345 MPa versus S355's 355 MPa — these are closely comparable. However, A36 (fy = 250 MPa) and S235JR (fy = 235 MPa) have a slight difference, so substitution requires a 6% area increase for equivalent axial capacity.

Frequently Asked Questions

What is the yield strength of S355 steel at 50 mm thickness?

S355 steel at 50 mm thickness falls in the 40 < t ≤ 63 mm bracket. Per EN 10025-2, the minimum yield strength is 335 MPa at this thickness range. The tensile strength remains 470-630 MPa.

What is the difference between S235JR and S235J2 mechanical properties?