45 Degree - Up to 1/2 Inch Stock Lock Miter Router Bit - 1/4 Inch Shank

(Easy to Create Lock Miter Joint. Then, cut one piece horizontally and the second one vertically. Cutting Height): 1-3/8" 1/2". Heat resistant Teflon coating to prevent building-up of sawdust, resin, and pitch.

eBay