US Patent No. D669,923 S
Traditional down cut spiral door bits on the market "Blow Out" material on the bottom side of the door after the bit dulls. Whiteside's Compression Door-Lite bit continues to perform after dulling because the material is "pulled" up instead of being pushed down. These bits are made with high grade tool steel and precision ground on state of the art CNC grinders.
Test results were conducted of the Whiteside Machine Up/Down Door-Lite Bit against traditional spiral door bits. Test cuts were performed on a CNC door cutting machine routing steel clad exterior doors. The traditional bit cut an average of 12,000 inches per bit, whereas the Whiteside Door-Lite bit cut an amazing 22,000 inches!