Brake Drum Refinishing Specifications
Brake Drum Specifications| DRUM DIAMETER (Maximum)  This marking includes 0.76 mm (0.030 inch) for allowable drum wear beyond the recommended 1.52 mm (0.060 inch) of drum refacing.  | Cast/stamped into outside surface of drum | 
| DIAMETER VARIATION (Maximum) | 0.0635 mm (0.0025 in.) in 30 degrees | 
| 0.0889 mm (0.0035 in.) in 360 degrees | |
| DRUM RUNOUT (on lathe) | 0.1524 mm (0.006 in.) | 
| INITIAL DRUM MACHINING CUTS  Initial machining cuts should be limited to 0.13 mm (0.005 in.) at a time as heavier feed rates can produce taper and surface variation.  | 0.13 mm (0.005 in.) | 
| FINISH DRUM MACHINING CUTS | 0.0254 mm (0.001 in.) |