When selecting robot hardware, you must prioritize mechanical precision, torque density, and material durability. For actuators and motors, ensure they offer high power-to-weight ratios and integrated encoders with high resolution (e.g., 17-bit or higher) for accurate positioning. For structural components, 6061 or 7075 aluminum alloy is preferred for its balance of weight and strength. Additionally, verify the IP rating (e.g., IP65 or IP67) if the robot will operate in dusty or wet environments to prevent ingress-related failures.