Fit perfectly in 3/8" cordless drill, used it to spot-till major section of 30 year old garden, that had suffered 2 years of neglect (health issues). Too congested to get even the little electric tiller in- worked perfectly, but had to sawzall through wisteria runners first. Only used it to go 8-12 inches into soil, and this was NOT the first tilling of the ground, that said, it did the job. Would recommend a 3/8" inch drill, if going cordless, for the added torque. Worked better than anticipateSee full review