16/20MnCrS5
16/20MnCrS5 (1.7149) – Alloy special case-hardening steel: Properties and specifications
16/20MnCrS5 (digital code 1.7149 according to EN standards) is a manganese and chromium alloyed special steel intended for case hardening. This grade is designed for parts requiring an extremely hard, wear-resistant outer layer alongside a tough, impact-absorbing core. Unlike standard 16MnCr5 or 20MnCr5 steels, this modification (S5) has a strictly controlled, increased sulfur content, which drastically improves machinability on cutting machines. UAB „Antėjas” offers high-quality 16/20MnCrS5 steel for your serial production projects with fast delivery across Europe.
1. What does the 16/20MnCrS5 designation mean?
- 16/20: Indicates a low carbon content (approx. 0.16–0.22%). This ensures excellent core toughness after case hardening and quenching.
- MnCr: Alloying with manganese (1.1–1.4%) and chromium (1.0–1.3%) ensures excellent hardenability, mechanical strength, and wear resistance.
- S5: Modification with an increased, strictly controlled sulfur (S) content (0.02–0.04%). By forming manganese sulfide inclusions, sulfur acts as a natural lubricant during cutting, facilitates chip breaking, and extends CNC tool life.
2. Chemical composition (according to EN 10084 / EN 10277-4)
| C (%) | Si (%) | Mn (%) | Cr (%) | P (%) | S (%) |
|---|---|---|---|---|---|
| 0.17 – 0.22 | Max. 0.40 | 1.10 – 1.40 | 1.00 – 1.30 | Max. 0.025 | 0.02 – 0.04 |
3. Mechanical properties and Hardness
Before case hardening, the mechanical properties are adapted for easy forming and cutting:
| Tensile strength (Rm), MPa | Reduction in cross section on fracture (Z), % |
|---|---|
| 550 – 680 | 57 – 62 |
- Soft annealed (+A) hardness: ~217 HBW.
- Treated to ferrite-pearlite structure (+FP): 152 – 201 HBW.
- Treated to improve shearability (+S): ~255 HBW.
After case hardening and quenching, the surface layer reaches an extremely high hardness (often 58–62 HRC), while the core remains tough and fracture-resistant.
4. Main applications
Due to the sulfur addition and excellent case-hardening properties, 16/20MnCrS5 is indispensable in the serial production of automotive and machinery parts where CNC machining dominates: gearbox components, gears, racks, camshafts, cardan shafts, half-shafts, piston pins, and control mechanism parts.
5. International equivalents
In the global market, this grade is often found under the ISO standard (ISO 20MnCrS5). It is also a direct, easier-to-machine alternative to standard 16MnCr5 (1.7131) and 20MnCr5 (1.7147) steels.
Need 16/20MnCrS5 steel for your engineering project?
Looking for high-quality steel blanks for your serial production that require flawless machinability? Contact our team – we will promptly provide a commercial offer and organize fast delivery directly to your factory.