EN 10083: Quenched & Tempered Steels
EN 10083 covers the heat treatable engineering steels that most loaded forgings are made from. When a European drawing calls for 42CrMo4 +QT, this is the standard defining what that suffix obliges the supplier to deliver.
EN 10083 is the European standard for heat treatable engineering steels, in three parts covering delivery conditions, non-alloy grades such as C45 and alloy grades such as 42CrMo4. Suffixes like +QT (quenched and tempered) define the supply condition contractually, with properties tabulated by ruling section size.
- Standard
- EN 10083-1/2/3
- Common Grades
- C45, 42CrMo4, 34CrNiMo6, 51CrV4
- Delivery Conditions
- +QT, +N, +A, +AC
- Properties
- Tabulated by ruling section
- Indian Counterparts
- EN8, EN19, EN24
- Applies To
- Heat treatable engineering steels
EN 10083: Quenched & Tempered Steels at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Standard: EN 10083-1/2/3
- Common Grades: C45, 42CrMo4, 34CrNiMo6, 51CrV4
- Delivery Conditions: +QT, +N, +A, +AC
- Properties: Tabulated by ruling section
- Indian Counterparts: EN8, EN19, EN24
- Applies To: Heat treatable engineering steels
The Three Parts
Part 1 covers general technical delivery conditions, part 2 non-alloy steels such as C45, and part 3 alloy steels including 42CrMo4, 34CrNiMo6 and 51CrV4. The part number tells you which family a grade belongs to.
- Part 1: delivery conditions
- Part 2: non-alloy grades (C45)
- Part 3: alloy grades (42CrMo4)
- Grades named by composition
Delivery Condition Suffixes
+QT means quenched and tempered, +N normalised, +A annealed, +AC soft annealed. The suffix is a contractual obligation with defined property requirements — ordering 42CrMo4 without one leaves the condition unspecified and therefore unpredictable.
Properties Depend on Section
The standard tabulates mechanical properties by ruling section, because hardenability limits what a thick part can achieve. A 42CrMo4 forging at 250 mm section will not reach the properties quoted for a 40 mm one, and the standard says so explicitly.
Topics covered on this page
- EN 10083 standard
- 42CrMo4 EN 10083
- quenched tempered steel standard
- EN 10083-3 alloy steels
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What does +QT mean on a steel grade?
+
Quenched and tempered — the material is supplied heat treated to the strength and toughness the standard tabulates for its section size.
Is 42CrMo4 the same as EN19?
+
They are close equivalents. 42CrMo4 is the EN 10083-3 designation; EN19 is the older British designation for essentially the same Cr-Mo steel.
Why do properties change with section size?
+
Hardenability is finite. A thick section cools more slowly at its core, so it cannot reach the same strength as a thin one in the same grade.
Do you supply to EN 10083 conditions?
+
Yes, with heat treatment records and mechanical test results verifying the specified delivery condition.