Koopi 76mm / 3 Inch BI-Metal Hole Saw with Arbor and Replacement Pilot Drill Bit, Hole Cutter for Easily Drilling Wood, Plastic, Thin Metal

Worked great for my wood project so I can't say how it will do on any other material.

Very good for its value very strong and very sharp

It seems like a well made hole saw with one exception, the chuck bit that connects the hole saw to your drill has the threads in the wrong direction such that when you are drilling out a hole, the hole saw unscrews itself and is basically loose/floating. Have had it fly off and fall to the ground several times. Given the teeth on the hole saw are quite sharp, it does become dangerous, and I actually had my hand cut from it once. I do not know why they didn't provide a better mechanism from keeping the hole saw tight (kind of like how Milwaukee has those two pins that go into hole saw) or make threads reverse threaded such that it would actually tighten itself when you are using the saw.

I needed to make a repair on a sealed piece of machinery. This hole saw let me make a perfect access hole in the heavy sheet metal. For the price, I figured I only needed to use the hole saw one time. I didn't even use any cutting oil. I kept the drill running at a fairly low, constant speed building minimal heat. The saw had no trouble cutting through the sheet metal. The paint on the teeth is still almost completely intact.

I picked up this 4-1/8" Koopi Hole Saw for a quick wood panel job—truthfully not expecting much at this price point. But it more than held its own. The clean-edge design is legit: no binding, no splintered mess, just a neat circle that made my project look pro-level even with my less-than-perfect drill technique. The little spring on the pilot bit? A small thing that makes a big difference. Instead of wrestling with the wood disc after each cut, the spring pops it right out like it’s showing off. That saved me more time and frustration than I expected. Build-wise, the M42 Bi-Metal and HSS combo feels sturdy—I wouldn’t use it for heavy metal work, but for wood and plastic it’s reliable. I used a standard 3/8” drill and had zero issues with the arbor fit or wobble. The extra pilot drill bit and hex key were nice touches, though I wish it came with a little storage case to keep everything together. Bonus moment: I used it while remodeling my nook space, and it carved a perfect port for my recessed LED puck lights. One-and-done without needing to sand the edges—exactly what I needed.

Simple design with excellent machining, that cuts clean and easy. Comes with an extra bit!

works as advertised but the arbor or mandrel (which is otherwise designed well) does not fit well onto hole saw- had to drill out the locking holes to screw arbor fully, a bonehead machining error but all else is good

We'll worth the money for wood or plastic . Not sure how it will work on steel or stainless but worth a try . Very well built heavy. Comes with extra bit and tool .

Sorprendido con la calidad que tiene ,me ha durado mucho !, recomendado el sacabocados!

Works like it should... I'd buy again...

Didn't want to invest $50 in a Milwaukee hole saw, so online I go. I only needed to go through wood and some plastic, but figured I'd get something that could be used in the future should the rare occasion reoccur. This one came with some extra bits as well, that was a welcome find. It worked without issues for me and as it's job is currently done, it can now take a place to the other hole saws I've purchased over time.

cuts well