3/8" diamond coated twist drill bits for power tools. These tools are machined from high quality stainless steel, then coated with diamonds using a proprietary multi-layering process. This means faster, smoother cutting and less heat buildup. These diamond coated twist drills are used in a variety of commercial, and industrial uses. The shank size is identical to the head size. Head and shank diameter is 3/8". The diamond coating extends appoximately 1/2" from the tip. Availability: Usually ships in 2-3 business days. $20.00 Thank you for visiting A&M Instruments, Tools and Machining. Please e-mail any suggestions or comments to improve the site, our service, or tool selection. Always wear proper eye protection and gloves when using any cutting or grinding tool. ALL diamond tools last longer if a lubricant or coolant is used during cutting or grinding. Copyright® 2002-2006 A&M Instruments Inc 1-866-264-4287