16MnCrS5 (1.7139) Case-Hardening Steel

16MnCrS5 (material number 1.7139) is a typical free-machining alloy case-hardening steel; within the European industrial sector, it is widely used for components such as gears and shafts that require a combination of high surface hardness and core toughness.
 
The compositional design of 16MnCrS5 emphasizes "carburizing performance + machining efficiency":
C (approx. 0.14–0.19%): Low carbon content ensures core toughness
Mn (1.0–1.3%): Increases hardenability
Cr (0.8–1.1%): Enhances wear resistance and hardening capability
S (0.02–0.04%): Improves machinability
 
Summary of 16MnCrS5 compositional characteristics:
Easy to machine (sulfur content boosts machining efficiency); high surface hardness after carburizing; excellent core toughness
 
16MnCrS5 steel heat treatment process:
Carburizing: 900–950°C
Quenching: 820–860°C
Low-temperature tempering: 150–200°C
 
16MnCrS5 steel performance characteristics:
Surface hardness: 58–62 HRC
Core strength: Good
Wear resistance: Excellent
Fatigue resistance: Outstanding
 
16MnCrS5 is widely used for:
Gears and gear shafts
Automotive transmission components
Sprockets and worm gears
Mechanical transmission parts
High-wear-resistance sleeves and bushings