Material number 1.8974: S700MC
1.8974 is the European material number (Werkstoffnummer, EN 10027-2) for S700MC, thermomechanically rolled ultra-high-strength steel for cold forming specified in EN 10149-2.
What 1.8974 means
EN 10027-2 material numbers have the form 1.XXYY: the leading 1 is steel; the next two digits give the steel group (89 → group 89); 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 1.8974 has stayed constant while the symbolic name moved from QStE690TM to S700MC.
S700MC at a glance
S700MC is the strongest grade most cold-forming shops will ever roll: an EN 10149-2 thermomechanically rolled strip with 700 MPa minimum yield and 750–950 MPa tensile, still weldable and bendable at 10–12 % elongation. Werkstoff number 1.8974; QStE690TM in the old German nomenclature, Domex/Strenx 700 MC in the trade. The metallurgy is a very low carbon (≤ 0.12, typically 0.06 %) fine-grained ferrite–bainite matrix strengthened by Ti, Nb, V and Mo precipitates and, in some mills, boron — controlled rolling and accelerated cooling do the rest.
It exists to take weight out of structures: a crane boom, trailer chassis rail or tipper body in S700MC is 40–50 % lighter than the S355 equivalent for the same load, which is payload, fuel and reach. The price is stricter forming rules (bend radius ≥ 1.5–2.5 t, no hot forming, springback compensation), stricter welding heat input, and a fatigue design that respects the higher stresses.
There is no exact ASTM equivalent in A1011 (Grade 80 stops at 550 MPa); SAE J1392 100XF and mill grades cover the US market. For plate above about 12 mm the quenched-and-tempered S690QL (EN 10025-6) is the alternative.
Full data sheet for S700MC → · Equivalent grades →