Koopi 4.25 Hole Saw with Heavy Duty Arbor, 38mm Depth Bi-Metal 4 1/4 inch Hole Cutter for Easily Drilling Wood, Plastic, Plywood, Drywall, Thin Metal (108mm)

Only used it once so far, to cut through the roof, but it is heavy duty, cuts well and easy to use.

At a large hardware store this will cost you over $30. Here it was a fraction of the cost without compromising the quality. I was installing a laundry exhaust and had to cut through aluminum siding asphalt siding and plywood for a total of 3 inch thickness wall. I did have to do it in increments because of the depth of the hole saw but that is to be expected.

Cut through fibreglass easily

I used this to drill one hole through steel siding, osb and some spray foam insulation in order to vent a bathroom basement exhaust fan. It worked perfect for my single hole. I ran it backwards at the beginning of the cut so it didn’t catch and I had a nice clean hole in the end.

Gave to someone

Used on 1 1/2” floor joist had to auger out pilot hole 3/8” to get the depth

I was tall was as described I recommend using your drill and reverse when sawing sheetrock

Although they seemed a little pricey...the investment was well worth it. I purchased the 6 1/2 and 4 1/4 sizes for my 6 and 4 Torchstar Slim LED lights (purchased on Amazon) and they were amazing. I added 40 lights and these paid for themself after 5 in my opinion. Make sure you have a 1/2 drill, i didnt read that part so I borrowed a friends, I had a 3/8.

Sawed over 100 holes thru wood for a ice-cream cone craft stand. Worked perfect.

I HAD 50 LIGHTING ADAPTERS TO MAKE THAT I NEEDED TO MAKE A 6-3/8 HOLE IN 3/4 PLYWOOD TO INSTALL A WAFFER LIGHT IN , AND A SKILL SAW WAS GOING TO TAKE FOR EVER. SO I OREDRED THE HOLE SAW AND MADE A FIXTURE TO HOLD THESE IN A DRILL PRESS AND THE SAW DID THE TRICK SLICK AND EASY, QUALITY WAS GREAT COMPAIRED TO HIGH PRICED UNITS IT COMES WITH 2-DRILL BITS AND THE HOLDING ADAPTER AND HEX WRENCH, WOULD BUY AGAIN!!!