Mechanical Parts
INDUSTRY APPLICATION
Mechanical parts span a vast range — from bearing housings and couplings to hydraulic cylinders. Rising demand for precision ball screws, linear guideways, and robot reducer gears has raised the bar for steel dimensional accuracy and performance consistency.
Carbon Steel Round Bar
Carbon steel is the highest-volume material in mechanical parts. Low-carbon S10C/S15C/S20C is soft and machinable — ideal for pins, washers, and bushings, and as base material for carburized parts. S45C is the "universal steel" of mechanical parts, widely used for drive shafts, connecting rods, and structural parts after Q&T. S50C/S55C suit cams, ratchets, and clutch components needing higher hardness. For ball screws, S45C/S55C with induction hardening achieves high surface hardness while keeping the core tough, balancing wear resistance with bending resistance.
Alloy Steel Round Bar
Alloy steels serve higher-stress, tighter-tolerance applications. SCM415/420 carburized gives "hard surface, tough core" for gears, cam shafts, and eccentric shafts. SNCM220 (8620) leads its class in case impact toughness for heavy-duty gears and spline shafts. Robot reducer gears are the premium application — harmonic and RV reducer gears transmit extreme torque in minimal space with ultra-low backlash requirements. SCM420H and SNCM220H with guaranteed hardenability bands ensure consistent hardness profiles and distortion across every batch.
Bearing Steel SUJ2
SUJ2 (AISI 52100) is the standard material for all rotating machinery components. This high-carbon chromium bearing steel achieves extreme hardness and wear resistance after quench and temper, with the strictest non-metallic inclusion requirements of any steel grade — microscopic inclusions under high-speed rotation become fatigue crack initiation sites. SUJ2 covers ball screw balls, linear guideway rollers, precision bearing rings, and rolling elements, as well as gauges, guide wheels, and high-precision locating pins.
Precision Ground Bar
Ball screw shaft blanks require strict straightness and OD tolerances — ground bar eliminates straightening and rough-turning steps before screw grinding. Linear guideway rail blanks benefit from ground bar's superior starting surface finish, reducing final grinding allowance. Hydraulic cylinder rods, pneumatic rods, and guide pillars in direct contact with seals depend on ground bar's surface quality to prevent premature seal wear and leakage.
Free-Cutting Steel
Free-cutting steels handle the high-volume standardized parts produced on automatic lathes: hydraulic fittings, pneumatic connectors, valve spools, and bushings. Short cycle times but large total quantities make cutting efficiency a direct cost driver. SUM22 covers general-precision parts; SUM24L with lead addition delivers superior machinability for high-precision valve spools and precision bushings.