The drill's mandrel shank is not hex (it's actually an odd shape I've never seen before) and will not fit 3/8" hex shank, therefore it is not compatible with the cordless drill I use. I couldn't return it as Revain's return policy is only 1 month and I missed it by 4 days :(This boring bar information is not provided by the seller so you have no idea. If you have a power tool with an adjustable shank clamp, it can fit, but again remember that it's not hexagonal.