Set includes three solid micrograin carbide bits that cut quickly and smoothly with a long-life cutting edge. These upcut spiral bits produce a clean and accurate cut with minimal chatter. They are perfect for mortise and tenon joints as well as removing material. Set includes the following upcut spiral bits: SRB-5146 (1/4" diameter), SRB-7467 (3/8" diameter) and SRB-7468 (1/2" diameter).