YONICO Stepped Rabbet Router Bit 1/4-Inch Glass 1/2-Inch Shank 18126
This bit will rabbet the back of a frame allowing ample space for artwork, glass and backing. The double stepped rabbet will cut a 3/8" wide x 1/4" high rabbet for a glass or mirror, and an additional 3/8" wide x 5/16" high rabbet for your artwork and backing board. Two flute carbide cutters with ball bearing guides. Bit shank is 1/2".