RC-49496. In-Tech Insert Corner Round 1/8 Radius x 1 Inch Dia x 3/8 x 1/4 Shank. These popular insert router bit profiles provide all woodworkers access to the industrial-grade technology, at an affordable price. By replacing worn knives instead of sharpening standard carbide tipped bits, router bit dimensions, cutting quality and accuracy remain constant during the life of the tool.