Although not covered in USDA Standards, Medium Pieces are a common size classification used in the California walnut industry.
No less than 98% may pass through a 32⁄64 inch (12.7 mm) screen.
No more than 3% of that 98% may pass through a 16⁄64 inch (6.35 mm) screen.
No more than 1% of the 3% may pass through 8⁄64 (3.18 mm) screen.
