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)

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.

This little saw cut 8 holes through Hardy Soffit and I beleave it remains sharp enough to cut 8 more

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

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.

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.

This product came disassembled, with no instructions in the box. Ive been in construction for forty years, and Ive used lots of tools with arbors. But this arbor was a new one on me. I tried for a half-hour to figure out how to put it together. Finally had to go to computer and take a close look at the item on the Amazon page. Also, be aware assembly will probably require use of a pair of split-ring pliers. Once assembled, it did a good job cutting through 1 pine siding and 1/2 flakeboard sheathing using only a P-C cordless drill. Be aware, though, that advertised 1 1/2 cutting depth is shall we say optimistic. Id say 1 1/4 is more like it. For example, I dont think you could cut a hole through a 2x4 without coming at it from both sides.

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.

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

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.

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!!!