I purchased this hole saw to cut a disc from 1/4" thick sheet steel to make a spare tire carrier. Blank removed from hole The diameter of the Saw is approximately 7" - ideal for fittings 5" x 4.5". I turned it on a drill at 170 rpm and used 30 viscosity engine oil as the cutting fluid. The slight wobble was well within my expectations for the a bit of that diameter. To successfully cut 1/4" steel plate with this bit (or any other bit) without damaging the bit, you must slowly rotate, cool and lubricate, and apply slow, steady downward pressure exercise The photo shows a disc with a welded pilot hole and studs welded to the back of the plate. The studs are 1/2"-20 x 1-3/4" grade 8 screws.