42CrMoS4 (+QT)
42CrMoS4 (1.7227) – Alloy special steel: Properties, applications, and technical specifications
42CrMoS4 (digital code 1.7227 according to EN standards) is a chromium-molybdenum alloyed special steel intended for quenching and tempering (+QT). This grade offers exceptional strength and resistance to dynamic loads. Unlike standard 42CrMo4 steel, this modification features a strictly controlled sulfur content, which significantly improves machinability. UAB „Antėjas” offers a wide range of this steel – including forged steel rings and thick-walled hollow cylinders – with fast 3-5 day delivery across Europe.
1. What does the 42CrMoS4 designation mean?
- 42: Indicates a medium carbon content (approx. 0.42%), ensuring excellent hardness after thermal treatment.
- CrMo: Alloying with chromium (0.9–1.2%) and molybdenum (0.15–0.30%) guarantees deep hardenability and fatigue resistance.
- S4: A modification with increased, strictly controlled sulfur (S) content (0.02–0.04%). This forms manganese sulfide inclusions that act as a natural lubricant during cutting, breaking chips efficiently and extending the tool life of CNC machines.
2. Chemical composition
| C (%) | Si (%) | Mn (%) | P (%) | S (%) | Cr (%) | Mo (%) |
|---|---|---|---|---|---|---|
| 0.38 – 0.45 | Max. 0.40 | 0.60 – 0.90 | Max. 0.025 | 0.02 – 0.04 | 0.90 – 1.20 | 0.15 – 0.30 |
3. Mechanical properties (+QT condition)
| Diameter (mm) | Tensile strength (Rm), MPa | Yield strength (Re), MPa | Elongation (A), % |
|---|---|---|---|
| Up to 16 mm | 1100 – 1300 | 900 | 10 |
| 16 – 40 mm | 1000 – 1200 | 750 | 11 |
| 40 – 100 mm | 900 – 1100 | 650 | 12 |
| 100 – 160 mm | 800 – 950 | 550 | 13 |
Hardness (HBW): Soft annealed (+A) condition is approx. 241 HBW, and treated for improved shearability (+S) is approx. 255 HBW.
4. Main applications and Equivalents
Due to the sulfur addition and high strength, 42CrMoS4 is ideal for serial production requiring fast CNC machining: highly loaded shafts, axles, gears, forged steel rings, and hollow cylinders.
International equivalents: USA: 4140, France (AFNOR): 42CD4u, Spain (UNE): 40CrMo41, ISO: 42CrMoS4.
Need 42CrMoS4 steel for your production?
Looking for strong forged rings, shaft blanks, or hollow cylinders? Contact our team for a commercial offer and fast delivery directly to your facility.