EN 10083-2 — Steels for quenching and tempering. Part 2: Technical delivery conditions for non alloy steels
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Scope
Non-alloy steels for quenching and tempering: C22 to C60 and their E (P ≤ 0.030) and R (controlled S) variants, plus 28Mn6. Specifies chemistry, hardenability, and mechanical properties in the +N and +QT conditions by ruling section. Part 1 covers general delivery conditions; Part 3 the alloy grades (42CrMo4 etc.).
Grades covered by EN 10083-2
| Grade | No. | Type | C % | Yield MPa | Tensile MPa | Nearest equivalents |
|---|---|---|---|---|---|---|
| C45 | 1.0503 | Medium-carbon steel for quenching and tempering | 0.42 – 0.5 | 340 | ≥ 620 | 1045, S45C, 45 |
Revision history and superseded standards
| Year | Change |
|---|---|
| 1991 | EN 10083-2:1991 — first edition replacing DIN 17200 unalloyed grades |
| 2006 | EN 10083-2:2006 — current; C35R/C45R/C55R free-machining variants, Table 5/6 revised |
Supersedes: DIN 17200:1987 (C45, Ck45, Cm45); EN 10083-2:1991.
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The full text is copyrighted by CEN and is not reproduced here. Purchase the current edition from CEN or your national standards body. The values on this site are the normative limits as published; the standard's own tables, notes and test methods govern.
Related standards
Quenched and tempered means the condition is the product
A steel under EN 10083 is sold by what heat treatment it will take, not by a strength it already has. The same C45 bar exists as +N normalised, +QT quenched and tempered and +A annealed, and the mechanical table that applies depends entirely on which one is on the order.
Part 2 covers the non-alloy grades — C22 to C60 and their E and R variants — where the only strengthening mechanism is carbon. That sets a hard limit: hardenability runs out with section size, and a 100 mm bar of C45 cannot be through-hardened however carefully it is quenched. The standard therefore states properties against a limiting ruling section, and quoting a tensile band without the diameter it applies to is quoting half a specification.
E and R suffixes, and why they cost money
C45 comes in three sulphur variants and they are not interchangeable. Plain C45 leaves sulphur at the ordinary level. C45E caps it at 0.035 % — cleaner steel, better transverse ductility, the choice for parts that will be heat treated and loaded. C45R specifies a controlled sulphur *range* for machinability, deliberately adding what E removes.
The practical rule is E for duty, R for the lathe, plain for general work. Ordering R where a fatigue-loaded shaft was designed gives a part that machines beautifully and has measurably lower transverse toughness.