【Product Specifications】 Drilling diameter: 21mm | 13/16" Drilling depth: 60mm | 2-3/8"; Round shank: 8mm | 5/16";Total length: 90mm | 3-1/2, Package includes 1Pcs Forstner drill bit 【High Quality】：We use 2.0mm thick YG8 industrial grade alloy.The strength of YG8 is divided into industrial grade＞professional grade＞general grade 【Easy Work】 It is easy to make flat-bottomed and pocket holes without chipping on any wood, plywood, MDF, chipboard, as well as plastic, rubber, and fiberglass during processing or installation 【Ultra-High Precision】Our factory is dedicated to designing various special sizes that the drilling error for each size is within 0.1mm If you have any other size requirements or questions, please contact us at any time. Enjoy the fun of woodworking with ease of mind 【Warm Tips】Smaller forstner drill bits can be used with a standard handheld drill. For larger forstner bits, it's best to use a machine with good stability for drilling, such as drilling machines, bench drills, vertical drilling machines, or vertical electric drills. Hardwood, please purchase standard sizes; for softwood, please select sizes that are smaller than the standard size by 0.2mm-0.5mm 【Note】Do not use on concrete, steel plates, ceramics, or glass. Professional woodworking tools have sharp blades; please ensure that non-professionals do not handle or play with them 21mm | 13/16inch Carbide Forstner bit, 2.0mm thickness of YG8 carbide, Woodworking hinge cutter tool kits for wood, plywood and plastic by CENYB