If you are working with rough materials, like strong metal alloys, or machine installation, then you might need a adjustable hole saw which can shrink or expand the diameter of its rim to create holes of different sizes.
Hole saws are usually able to cut holes through materials like steel, aluminum, copper, brass, stainless steel, wood, sheet metal, plastic, and other machinable materials. Once these materials have hole cut, or sawed, into them, then they are able to allow things like pipe, tubing, doorknobs, etc. to be installed.
