Material number 1.7225: 42CrMo4
1.7225 is the European material number (Werkstoffnummer, EN 10027-2) for 42CrMo4, chromium-molybdenum steel for quenching and tempering specified in EN 10083-3.
What 1.7225 means
EN 10027-2 material numbers have the form 1.XXYY: the leading 1 is steel; the next two digits give the steel group (72 → Cr-Mo steels < 1 % Cr); 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 1.7225 has stayed constant while the symbolic name moved from 42CrMo4 (1.7225) to 42CrMo4.
42CrMo4 at a glance
42CrMo4 is Europe's most-used alloy steel for quenched-and-tempered parts: 0.42 % C, 1 % Cr, 0.2 % Mo, Werkstoff number 1.7225, specified in EN 10083-3. The chromium–molybdenum combination gives deep hardenability — a 40 mm bar through-hardens in oil — and resistance to temper embrittlement, so the same bar can be tempered anywhere between 550 and 650 °C to hit a strength band from 900 to 1300 MPa.
It is the steel of crankshafts, gearbox shafts, high-strength bolts (10.9 and 12.9), hydraulic components and drilling tools. Machinability in the soft-annealed condition is fair; most parts are rough-machined at 240–300 HB in the pre-treated (+QT) condition and finished after nitriding or induction hardening.
42CrMo4 and AISI 4140 are the same steel for practical purposes, as are JIS SCM440, GB 42CrMo and BS 708M40; the cross-reference table below grades each match.
Full data sheet for 42CrMo4 → · Equivalent grades →