Hole Saw 4-inch Dia Hole Cutting Drill Bit for Drilling Holes in Wood, Plastic, Drywall, Thin Metal

My girlfriend and I decided to take on a full bathroom remodel. I'm a simple weekend-warrior, youtube mechanic/dyi'er so no professional experience going into this project. We installed an exhaust fan in the bathroom that required ventilation to the exterior of the home.I was nervous to drill a 4" inch hole through the side of my house as per the exhaust fan duct requirements but this attachment, with how nicely sharp the teeth were, didn't give me too much time to hesitate after I started drilling as it went completely through my cedar shingle and 2 pieces of plywood exterior within about 15-25 seconds. I was really impressed with how sharp it was and how perfectly clean the cut was. I gawked at how much similar hole cutters were at the big box stores and took my chances on this one and would easily take that chance again.

Cuts drywall nicely but had to remove the spring or the drywall circle will fall into the wall.

I had to do a little rework to the 4, small holes in the center. They pressed the center hole and then threaded it. The 4 holes around the center threaded hole rolled up on the press bend radius. They could have fixed this problem in a few seconds, but their arbor worked. I wanted to use my good arbor, so I am happy now this was a strange size and hard to find so I'm good with it now. I did the shiny stuff with a little cutter...

I got this because I needed a 75mm hole saw to drill a hole to mount a small fan. I was drilling though hardwood. The bit did a great job and produced a clean hole with minimal splintering.

Needed to make speaker holes for some 6.5s in my boat worked great went through the fiberglass and wood the template for the speakers asked for 147mm this was spot on

Used on drywall, works as advertised, would buy again.

I have plaster walls and have used Bi-Metal blades in the past to make holes with other hole saws. I don’t expect them to last long, but I should be able to get a couple holes out of them. The arbor was useless for the initial attempt, but the one provided seemed fine. I like my Spyder arbor better and the good news it fit! I had 6 lights to install so I had high hopes to get through this process. After 6 minutes those hopes were extinguished. The plaster was barely scratched, but the blade paint managed to leave me a nice outline of where the hole could have been. The teeth, unstable to break the surface, just wanted to bounce off the surface. After lots of fine dust and no progress I checked the blade to see the teeth were almost gone already. Tried a few speeds., nothing worked. I deferred to my multi tool. I’m sticking to carbides going forward. Probably fine for Plywood or drywall, but didn’t last long enough to Find out.

Does the job