Material number 1.0570: St52-3
1.0570 is the European material number (Werkstoffnummer, EN 10027-2) for St52-3, general structural steel (DIN 17100, withdrawn) — today S355J2 / S355JR specified in DIN 17100.
What 1.0570 means
EN 10027-2 material numbers have the form 1.XXYY: the leading 1 is steel; the next two digits give the steel group (05 → steels 0.25–0.55 % C or Rm 500–700 MPa); the last two digits are a sequential number within that group. The number is unique to one composition and survives name changes, which is why 1.0570 has stayed constant while the symbolic name moved from St52-3 N → S355J2G3 → S355J2 (1.0577) to St52-3.
St52-3 at a glance
St52-3 was DIN 17100's higher-strength structural steel: 52 kp/mm² (≈ 510 MPa) minimum tensile and 355 MPa yield, material number 1.0570. It came in two impact classes — St52-3 U tested at +20 °C and St52-3 N (normalized) at −20 °C — and, together with St37-2, it made up almost the whole German structural market for forty years. DIN 17100 was withdrawn in 1994, but 'St52' remains the everyday name for S355 in Germany, Austria, Turkey, Poland and much of the Middle East, and 'ST52' appears in countless hydraulic-cylinder and crane specifications.
The EN 10025 mapping is straightforward: St52-3 N → S355J2 (1.0577), St52-3 U → S355JR (1.0045). The yield table is unchanged; EN lowered the minimum tensile to 470 MPa, tightened P and S to 0.025 % for J2, and dropped the DIN N-limit. Cold-drawn hydraulic tube sold as 'ST52' is the tube lineage (DIN 2391 St52 → EN 10305-1 E355), not the plate grade — a frequent source of confusion.
Internationally, ASTM A572 Grade 50, JIS SM490, GB Q355B and GOST 09G2S are the 'near' matches; none carries exactly the St52-3 N combination of 355 MPa and −20 °C impact.
Full data sheet for St52-3 → · Equivalent grades →