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)

I needed the 6 3/8 hole saw to install a duct for a range hood through four kitchen cabinets. The Koopi is a heavy duty unit, accent on heavy, and the one I received seems round and well balanced. Learn-by-doing experience: I found that my 20 volt Dewalt drill is adequate for this saw, but I wouldnt want to use anything smaller. The saw is unwieldy to use, especially in the top of a wall cabinet where keeping the saw parallel to the cutting surface is a challenge. Using the drills clutch to keep the drill from spinning dangerously when the teeth bind in the wood was the only way I could manage it. This way when the saws position isnt just right the drill clutch engages; when the hole saw is correctly placed the teeth do their job fairly well. It did take some time to cut each 1/2 inch deep hole--and my high end Dewalt drill got very hot--but the saw worked well. Ive cut seven plywood holes so far and the saws teeth dont seem too worn yet. This is a pretty good tool for something I only need for one job.

This hole saw worked great for installing some recessed lighting, however I’d be concerned about the longevity of this product solely due to the fact that I only installed 4 and a few teeth were getting dull (ONLY from drilling through sheet rock/drywall). I’m sure for the average consumer wanting to use it as a one time or very seldom tool in order to install recessed lighting, it’ll be great however if you’re in a trade where you perform this type of work quite often I would look to invest in a name brand hole saw.

Ordered this hole saw to install ceiling cans. It works great on the first three. After that It dulled quickly.

This was purchased to drill a vent hole into the side of a dryer. With a little cutting oil, the holesaw cut right through the outter and the inner panels. Now Im not saying that this tool would cut the same holes all day long, all I am saying is the tool did what I needed done, which was a 4 hole in the side of the ol;d bags new dryer. Pressure off. Well worth the price.

This worked well for cutting out holes for my can lights. The hole saw is much heavier than I thought and the the peg holes on the side are very much needed to keep the center from slipping/stripping while you drill. Some other brands offer a spring on the bit to kick out your wasted center but at least for my drywall, this wasnt an issue. I could see this being a slight pain with wood but not a deal breaker. A few downsides however is that when you thread your drill bit assembly, there is still 1/16 or so that you could tighten to get it to seat completely BUT then the side pegs wouldnt be able to seat in their respective holes so youre left with backing it off a bit. One thing I was not expecting that you should be aware of when cutting something more heavy duty like wood is that due to its weight, this thing will act like a car flywheel and have enough inertia to kick out your drill so I definitely recommend double hand holding your drill or better yet, using one with a side thread handle.

I bought this to drill 6 holes in my ceiling to install LED lights. It is a custom home from the early 70s, so the ceiling drywall has about an 1/8-3/16 of plaster finish. By the third hole, the teeth were 75% gone and it would not cut. I had to cut the remaining three holes with a key hole saw - that saw had no problem at all cutting the plaster-coated drywall. Im sure the plaster layer is more abrasive than plain drywall, but this bit is supposed to be able to cut through metal. I cant imagine this bit would hold up for very long in anything other than plain drywall. If thats how it was advertised, Id be fine with the outcome, but they represent this as a cuts anything bit, and that is very far from reality.

This was an awesome investment. I used it for cutting holes in drywall to install Round outlet boxes for lights.

This is sturdy. Good welds.

Fast shipping exactly what I needed

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.