Buyers should prioritize Induction Heating Power (kW) and Frequency (kHz), as these determine the heating depth and speed. For surface hardening, High-Frequency (100-400kHz) is ideal, while Medium-Frequency (1-20kHz) is better for deep penetration. Ensure the machine features an IGBT Inverter Module for energy efficiency and stable power output. Additionally, verify the Cooling System requirements, typically necessitating a Closed-Loop Water Chiller to prevent component overheating during continuous operation.