Material number 1.0039: S235JRH
1.0039 is the European material number (Werkstoffnummer, EN 10027-2) for S235JRH, non-alloy structural steel for cold-formed (EN 10219) and hot-finished (EN 10210) hollow sections specified in EN 10219.
What 1.0039 means
EN 10027-2 material numbers have the form 1.XXYY: the leading 1 is steel; the next two digits give the steel group (00 → base steels); 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 1.0039 has stayed constant while the symbolic name moved from RSt37-2 (Hohlprofil) to S235JRH.
S235JRH at a glance
S235JRH is what a box section, MS square tube or CHS made in Europe is certified to: the general structural steel S235JR delivered as a hollow section, H for hollow, under EN 10219 (cold-formed, welded) or EN 10210 (hot-finished). Werkstoff number 1.0039. Yield 235 MPa, tensile 360–510 MPa, 27 J at room temperature — the same numbers as the flat product, with the hollow-section standards adding the geometry, tolerances and sectional properties a designer needs.
Cold-formed EN 10219 sections are made on a tube mill from S235JR-quality strip, high-frequency welded, then sized square or rectangular; the corners work-harden, which is why EN 10219 quotes 24 % elongation against 26 % for the hot-finished EN 10210 product and assigns buckling curve c instead of a. For fences, furniture, canopies, racking, greenhouse and light building frames S235JRH is the default; for columns, trusses, cranes and anything designed to 355 MPa or needing −20 °C toughness, S355J2H is specified.
ASTM A500 Grade B, JIS STKR400 and GB Q235B are the market equivalents; all are slightly stronger on paper because of how their yield is measured on the formed section.
Full data sheet for S235JRH → · Equivalent grades →