1-Series Carbide-Tipped Hole Cutters have a 1" effective length and come with a center twist pilot drill and a safety collar stop. 3/8" shank on cutters up to 3-1/4" dia. and a 1/2" shank on cutters 3-5/16" dia. and larger. Tungsten carbide-tipped cutting edges last longer and can be run at higher feeds and speeds to create holes of exceptional quality and accuracy. One-piece construction; diameters from 9/16" to 4-1/2". Designed for use with hand-held drills – recommended drills include our EHB 16 series or other hand-held drills with slip clutch. Click on the CS Unitec link at the top of this page to see more industrial quality products from CS Unitec. Click on the CS Unitec link at the top of this page to see more industrial quality products from CS Unitec.