Grinder making metallic screech

A high-pitched metal-on-metal sound coming from the grinder during operation. Often appears suddenly after a grind adjustment or burr change.

Why it matters — Metallic screech almost always means the burrs are touching each other when they shouldn't be — either you've gone past the zero point during adjustment, or the burr carrier has loosened and the burrs are riding closer than designed.

Good to know

• Stop grinding immediately. Touching burrs damage themselves fast.
• Back off the grind setting to a known-safe coarse position, then carefully recalibrate the zero point. Re-torque the burr carrier if loose.