Selecting the correct frequency is critical as it determines the heating depth (skin effect). UHF machines typically operate in the 100kHz to 1.1MHz range, making them ideal for small-diameter workpieces, thin-walled tubes, and precision components. For power, you must calculate the thermal energy required based on the material's mass and specific heat capacity. Ensure the supplier provides IGBT or MOSFET power modules, which offer higher efficiency and better stability compared to older vacuum tube technologies.