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)

everything

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.

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.

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

Cut through fibreglass easily

Is easy to use does a great job. Thanks.

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.

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.

This is sturdy. Good welds.

Fast shipping exactly what I needed