20CrMnTi square steel is a versatile low-alloy case-hardening steel celebrated for its balanced blend of surface wear resistance and core toughness, with a square cross-sectional profile that elevates its structural utility across diverse industrial sectors. Its chemical composition is meticulously engineered to deliver optimal performance: carbon (0.17–0.23 wt%) forms the foundation for hardness; chromium (1.0–1.3 wt%) enhances hardenability and corrosion resistance; manganese (0.8–1.1 wt%) boosts strength and ductility; and titanium (0.04–0.10 wt%) refines the grain structure, preventing coarsening during heat treatment and improving overall toughness. These elements work in synergy to create a material that excels in both load-bearing and wear-prone applications. The manufacturing process begins with smelting in electric furnaces or converters, followed by continuous casting into billets. These billets are then hot-rolled through a series of precision square passes to achieve uniform cross-sectional dimensions and a smooth surface finish. Critical heat treatment steps—carburizing, quenching, and tempering—are applied to tailor its mechanical properties: carburizing infuses carbon into the surface to a depth of 0.8–1.2 mm, quenching (in oil or water) transforms the surface into hard martensite, and tempering reduces brittleness while preserving core ductility. Post-treatment, 20CrMnTi square steel exhibits impressive mechanical characteristics: tensile strength ranges from 1100 to 1300 MPa, yield strength hovers around 850 MPa, and elongation at break is approximately 10%. Its surface hardness reaches HRC 58–62, ideal for resisting abrasion, while the core remains relatively soft (HRC 30–45) to absorb shocks and vibrations—making it perfect for parts that need to withstand both wear and impact. The square profile makes it particularly suitable for components requiring even load distribution and stable mounting. In automotive manufacturing, it is widely used for gear shafts and differential components, where the square cross-section ensures secure coupling with other parts, reducing rotational slippage. In machinery, it serves as sprockets, connecting rods, and pins, leveraging its toughness to handle repeated stress. Construction equipment relies on it for structural elements that bear heavy loads uniformly, and agricultural machinery uses it for tiller parts, where its wear-resistant surface withstands soil abrasion and the core absorbs terrain-induced impacts. Compared to plain carbon steels, 20CrMnTi offers superior hardenability, allowing deeper case hardening for long-term durability. The titanium addition ensures a fine-grained microstructure, enhancing fatigue resistance. The square cross-section outperforms round profiles in applications where torque transmission or flat-surface mounting is critical, as it minimizes slippage and distributes stress more evenly. Overall, 20CrMnTi square steel is a reliable choice for industries demanding high-performance components that balance wear resistance, strength, and toughness, solidifying its status as a staple in automotive, machinery, and construction sectors.