On a California jobsite, stop and verify the grinder before putting a wrench on the flange nut. Disconnect the plug, remove the battery if it is cordless, and engage the spindle lock. Never rely on the switch being off.
The correct loosening direction depends on the grinder and its manufacturer. Check the arrow, manual, or markings near the spindle. On many models, the flange nut loosens opposite the wheel's running direction, but do not guess. Hold the spindle lock fully engaged, then turn the nut with the correct wrench. If it will not move with controlled pressure, stop and confirm the direction rather than forcing it.
After installing the new disc, keep the guard fitted and check that the disc matches the grinder's diameter, bore, accessory type, and maximum RPM. Confirm the flange orientation, clean seating surfaces, and tighten the nut securely without crushing the disc.
The skipped step is the safety verification. Rotate the disc by hand to check clearance, then stand clear and run the grinder briefly without cutting material. Watch for wobble, unusual vibration, rubbing, or noise. Shut it down immediately if anything seems wrong, disconnect power again, and inspect the disc, flanges, and spindle before returning to work.
