K-T Industries Sf-3 3/8" Tree Radius 1/4" Shank (3/8" x 1/4")
Solid carbide burs are the best value for the money. Although the initial purchase price is higher, carbide burs last 40 to 50 times longer than special steel burs. 1/4" shaft. Packaged in clams for easy retail display. Maximum RPM 18,000.