This Larger Adapter / Arbor fits all our Tungsten Carbide Grit Hole Saws over 1 1/8" Diameter through to our big 6" (152mm) Diameter Tungsten Hole Saw They come with the standard 5/8" thread and locking pins. Free Hex Key included to tighten the Tungsten Carbide Pilot Drill The End on this Mandrel / Arbor has this 7/16" Hex Shank but we also sell them with SDS fitting in our Store The main difference with these Hole saw Arbors Adapters is the fact that the Pilot Drills are basically Masonry Bits That means they have Tungsten Carbide Tipped Pieces welded into the tips This means they can drill through hard abrasive products and are designed to be used with a Hammer Drill. After All whats the Point Having a Hole saw that can cut the Tough Stuff if the Pilot Cannot? This makes them perfect for Drilling materials like Brick, Marble and Concrete. Pilot Drills are 8mm (5/16") Diameter and 1/4" Shaft dia. They are replaceable and available in our store. Notice our pilots have a flat area so the hex grub screw can secure Our 5/16" special Spear Point TCT Tile Glass Drill has a specifically designed 1/4" shaft. This means it will fit in any of our Adapters / Mandrels for drilling ceramic tiles without slipping. These Adapters / Arbors are designed to take serious abuse and will outlast conventional tools. They can be used in Corded or Cordless Drills with or without Full Hammer Action. They were intended to be used in conjunction with our Tungsten Grit Edge Hole Saws. So they can cut Tough Abrasive and Brittle materials like Brick, Masonry, Slate, Marble, Construction Materials such as Autoclaved Cement Board, Fibre glass, Composite Boards such as Chipboard and MDF, Laminates, Rubber Tyres, GRP, CFRP, Hardwood Flooring, Laminate Flooring, Plasterboard / Drywall, Soft Resinous Woods and Hard Brittle Materials. Check out our Extensions For Drilling Deep Holes available in 3/8" Hex and 7/16" Hex Fitting. Sign up for my email newsletters Check Out Our Store I Guarantee You Will Find "Another Amazing Product" The Important Stuff !!! We are a US Shipper based in Florida FL 34470 Everything we sell we have in Stock - We ship Fast within 24hrs. We aim to ship the same business day if ordered before noon We Ship Free within USA using USPS First Class or Flatrate averaging 2-3 days. We will ship anywhere in the world USPS First Class International. International Shipping 7-14 days subject to custom delays in your Country. If you are happy with our service please tell a friend If you are not please tell me, I will fix it if I can. We want your custom. Sign up for my email newsletters You will be informed first of any new Products, Designs, Instructions, Videos or Inventions etc.