Material number 1.0026: S195T
1.0026 is the European material number (Werkstoffnummer, EN 10027-2) for S195T, non-alloy steel for welded and threaded tubes (water, gas, sprinkler, GI pipe) specified in EN 10255.
What 1.0026 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 1.0026 has stayed constant while the symbolic name moved from St33-2 / St 33 to S195T.
S195T at a glance
S195T is the only steel grade in EN 10255, the European standard for water, gas and sprinkler pipe that is screwed or welded — the pipe the trade calls GI pipe, black pipe, gas pipe or, by its old British name, BS 1387 Class B and C. The designation reads S (structural steel), 195 (minimum yield in MPa), T (tube). Werkstoff number 1.0026. Its strength is modest on purpose: the pipe is defined by its wall series — light (L), medium (M, old Class B) and heavy (H, old Class C) — and by a 50 bar leak test on every length, not by the steel.
Most S195T tube is high-frequency welded from S235JR-quality strip, hot-dip galvanized to EN 10240 A1 (≥ 55 µm zinc inside and out) and threaded BSPT to EN 10226-1 with a socket per bar. Sizes run DN 6 (⅛") to DN 150 (6"), 6 m long. Medium series is the potable-water and fire-sprinkler standard; heavy series adds wall for pressure and deeper threads.
ASTM A53 Grade A/B, GOST 3262 ВГП, JIS SGP and GB/T 3091 are the equivalents in their markets; where the tube is a structural member rather than a line, EN 10219 S235JRH is the right specification.
Full data sheet for S195T → · Equivalent grades →