The smallest, most losable piece is the flange nut. Pick up a replacement from Milwaukee. This kit comes with an extra flange nut for your 5/8" 11 spindle grinders. It also comes with a spanner to keep the nut tightened. The spanner is made of thick metal that will hold up to regular wear and tear on the jobsite.
Milwaukee 48-03-1050 Spanner/Flange Nut Kit Features:
Milwaukee 48-03-1050 Specifications:
Milwaukee 48-03-1050 Includes: