Purchased to drill holes in drywall for LED lights. The saw drills holes that are the perfect 6" diameter that I measured. The problem, not related to this tool, is that there are small ribs on the sides of the jig being installed that will make a slightly larger hole than 6". I'm just going to use a drywall saw to cut some grooves around the perimeter of the hole. I'd say if you use this all the time you should probably try to find one about 1/4" larger to accommodate to prevent this. The saw is very strong and quite heavy so it looks like it will cut a lot of holes in the drywall. I will probably never use it to saw wood so can't comment on that. The mandrel included is not a locking type so I just tightened it really hard and it worked fine, it tightens even more since it doesn't have the small pins on the more expensive models.