Trades › Flush Trim Router Bit Image 1 of 2 Image 2 of 2 Flush Trim Router Bit $20.00 This router bit pairs perfectly with the hinge jig. It has a ¼ inch shank and a 19mm cutting head. Add to Cart Added! This router bit pairs perfectly with the hinge jig. It has a ¼ inch shank and a 19mm cutting head.