September 2021
Craftsman’s Cribsheet #100
Built Up Edge (BUE) is the accumulation of workpiece material onto the rake face of the tool. This material welds under pressure and is separate from the chip. Schools teach that this is because the first material to contact the tool work-hardens, and hardness tests to confirmed this. Because BUE changes the effective geometry of the tool, it can have either positive or negative effects