Structural Steel

S355JR · 1.0045

Also known as St52-3 / A572 Gr.50 / SM490

High-strength low-carbon structural steel for load-bearing frames and profiles.

S355JR (material 1.0045, formerly St52-3) is a high-strength low-alloy structural steel with a minimum yield strength of 355 MPa and good weldability. One of the most widely used grades for steel structures, it is supplied as bars, cold-drawn bar, merchant sections and profiles (IPE, UPN, HEB), plate and sheet.

International equivalents.

The same steel by country and standard — near matches; mill certificate governs.

S355JR (1.0045) · EN St52-3 · former DIN A572 Gr.50 (near) · ASTM SM490 (near) · JIS Q355 · GB

Chemical composition.

Indicative, % by weight per EN 10025-2. Mill certificate governs.

Element%
C ≤ 0.24
Si ≤ 0.55
Mn ≤ 1.60
P ≤ 0.035
S ≤ 0.035
N ≤ 0.012

Mechanical properties.

Indicative; depends on dimension and heat treatment.

Yield strength (Re)
≥ 355 MPa (≤ 16 mm)
Tensile strength (Rm)
470 – 630 MPa
Elongation (A)
≥ 22 %

Available forms.

Round bar Flat bar Square bar Equal angle Bright / cold-drawn bar Profile (IPE/UPN/HEB) Plate / sheet

Size range: Bars Ø 8–250 mm · profiles per section

Typical applications.

  • Steel structures & frames
  • Bridges & platforms
  • Industrial buildings
  • Heavy fabrication
Standards: EN 10025-2EN 10277

FAQ.

What is S355JR?

S355JR (material 1.0045, formerly St52-3) is a high-strength low-alloy structural steel with a minimum yield strength of 355 MPa and good weldability. One of the most widely used grades for steel structures, it is supplied as bars, cold-drawn bar, merchant sections and profiles (IPE, UPN, HEB), plate and sheet.

Is S355JR the same as St52-3?

Yes — S355JR is the European (EN) designation, while St52-3, A572 Gr.50, SM490 are the matching names used in other countries and standards (for example AISI/SAE in the USA, JIS in Japan, GB in China, former DIN in Germany). They are near equivalents and may differ slightly in chemistry; the mill certificate governs the exact specification.

What are the international equivalents of S355JR?

S355JR corresponds to S355JR (1.0045) (EN), St52-3 (former DIN), A572 Gr.50 (near) (ASTM), SM490 (near) (JIS), Q355 (GB). Equivalents are nearest matches by country/standard; the mill certificate governs the exact specification.

In which forms is S355JR available?

S355JR is supplied as Round bar, Flat bar, Square bar, Equal angle, Bright / cold-drawn bar, Profile (IPE/UPN/HEB), Plate / sheet, in Bars Ø 8–250 mm · profiles per section.

What is S355JR used for?

Typical applications include Steel structures & frames, Bridges & platforms, Industrial buildings, Heavy fabrication.