Expand The Depth of The Drilling Hole The outer diameter of the chuck is 25/32 inches, and the minimum size hole drilled is 13/16 inches,This Forstner Bit Extension is suitable for 3/8 Inch Round or Hex Shafts Forstner Bits 10 Inch Forstner Bit Extension for 3/8" Round Shank Black Hole Saw Drill Chuck Extension Adding 8-3/4 inches Drilling Depth to Forstner Bit... The set sold includes: 1*10 Alloy Steel Forstner Bit Extension,2*Fixed nut,1*Hexagonal wrench Turners Select Forstner Bt 5 Pece Set | Forstner Bt, Wll Turner, Craft Supples Usa Sturdy Alloy Steel Material Material: High quality alloy steel, good toughness, high hardness, strong fatigue resistance, greatly enhancing service life 10 Inch Forstner Bit Extension for 3/8" Round Shank Black Hole Saw Drill Chuck Extension Adding 8-3/4 inches Drilling Depth to Forstner Bit for Wood Turners Furniture Carpentry and Construction,Funnytek,Forstner Drill Bits,Wood Drill Bits,Industrial Drill Bits,Cutting Tools,Industrial & Scientific Material: High quality alloy steel, good toughness, high hardness, strong fatigue resistance, greatly enhancing service life Easy to Use Nsert your standard Forstner drill bit into the extended rod clamp and The selection of nuts is also very important. Choosing high-quality nuts has much better fixing performance and is not easy to loosen Extra Long Drill Bit Extension Rods Steel 2-Piece - 169mm & 254mm Extra Long Drill Bit Extenders With Wrenches Forstner Bit Extension Set Features a collet with a 3/8 inch (9.7mm) inside diameter, designed with a tight tolerance to securely hold Forstner bits with shank sizes of 3/8 inch or slightly smaller. - Constructed from high-carbon steel, this extension is precision ground and polished for enhanced durability and sturdiness, ensuring long-lasting performance