Engraving Bits Decoded: Geometry, Grade, and Material Match

Rotary engraving bits look like tiny metal toothpicks, but inside each one hides four engineering decisions: head shape, flute count, helix angle, and carbide grade. This episode maps the full landscape of engraving geometries and compositions for handheld tools — from why a cone bit's flat floor controls stroke width to why C4 micrograin carbide is a brittle mistake on a low-torque Dremel. We break down the material-specific picks for HDPE, aluminum, MDF, and PCB copper, and explain why those 30-piece starter kits sabotage your technique with inconsistent grinding. Episode #202138 — open it directly at myweirdprompts.com/202138