Bits in these sets have profile and Groove or rabbet cutters and ball-bearing guide mounted on a 1/2" Shank. Respacing of the components should only be necessary - using the provided shims - after the cutters have been resharpened. Guide straight cuts with the fence; use the pilot bearing only for cuts on curved rails or stiles, #55439, diameter (D): 1-7/8, cutting height (B): 5/8 to 1-1/8, Shank (D): 1/2, overall length (L): 3-D/32, type: mission (straight), flutes: 2, C: 1/2, B1 for 1/4" Plywood: 3/16 to 9/32, B1 for 1/2" Plywood: 7/16 to 17/32, 55439 carbide Tipped adjustable mission style Straight instile and rail system 1-7/8 dia x 5/8 to 1-1/8 x 1/2 inch shank set