Final answer:
The limiting factor for how fast a drill or endmill can feed through any material is usually the amount of power available.
Step-by-step explanation:
The limiting factor for how fast a drill or endmill can feed through any material is usually the amount of power available. This is because cutting through a material requires a certain amount of force, and force is equal to power divided by speed. Therefore, if the power of the drill or endmill is fixed, the speed at which it can feed through a material will be limited. Additionally, the hardness and strength of the material being cut can also affect the maximum feed rate. Harder materials may require slower feed rates to avoid damaging the cutting tool.