A built-up edge condition on a cutting tool causes it to do what?

A built-up edge condition on a cutting tool refers to the accumulation of material that sticks to the cutting edge during the machining process. This phenomenon can lead to several changes in the cutting dynamics.

When a built-up edge forms, it can change the geometry of the cutting tool, which can lead to deeper penetration into the material being machined. The additional material that has adhered to the cutting edge can provide extra cutting capability, allowing the tool to engage more material with each pass. This makes the tool effectively "cut more deeply" than it would be able to without the built-up edge.

This condition can also lead to increased friction and potentially create a rougher surface finish, but the immediate effect of a built-up edge is the change in how deeply the tool interacts with the material. Therefore, the reason for choosing the answer that states the tool cuts more deeply is due to the mechanics of how built-up edge influences the cutting action and contributes to a different cutting experience than standard operations.