This M10 flat washer is used as a load-spreading spacer between a fastener head or nut and the mounting surface on the threshing drum and hydraulic system assemblies. It prevents galling and distributes clamping force evenly across the joint face. A missing or undersized washer can allow the fastener to embed into the casting, reducing clamp load and causing the joint to loosen under vibration. This original-manufacturer part matches the original material grade and surface finish, so it provides the same crush resistance and corrosion protection as the component it replaces. On reinstallation, verify the washer is seated flat and that the fastener is torqued to the specification for that joint.