4-In Bi-Metal Non-Arbored Hole Saw Spyder's hole saws feature variable tooth pitch geometry and bi-metal steel that make them the durable choice for making holes in wood with nails, metals and plastics. Use Spyder's Rapid Core Eject arbor system to remove cores without prying - drill hole, press button, pull back the hole saw, and eject the core. Cut at an angle, and use two adapters (second adapter sold separately) on one pilot bit to enlarge existing holes. All Spyder hole saws fit on Spyder Rapid Core Eject arbor/pilot bits, and on universal hole saw arbors. Durable bi-metal blades create smooth cuts in steel, stainless steel, nail-embedded wood, plastics and more Spyder's Rapid Core Eject arbor removes cores without prying, cuts at an angle, and enlarges existing holes Variable tooth pitch guarantess a fast clean cut through all material thicknesses up to 1-7/8-in Tough bi-metal steel provides long life in tough drilling applications Universal 5/8-18 thread uses Spyder Hex10 arbor/pilot bits or other universal hole saw arbors