china EX100 HITACHI SF Bottom Track Rollers Black Color Track Roller

Roller Shell: Forged alloy steel with induction hardening on the tread surface.

Surface Hardness: HRC 50–58 (hardened layer depth: 5–9 mm) for wear resistance.

Core Hardness: HRC 28–35 to withstand impact loads.

Shaft: Quenched and tempered for balanced strength.

Surface Hardness: HRC 50–55; Core Hardness: HRC 30–38.