JIECHENG Bi-Metal 4 inch Hole Saw with Arbor Mandrel for Cutting Wood,Cornhole Boards,Drywall,Plasterboard,Plywood,Steel,Aluminium,Brass,Copper,Zinc,Tin,102mm

worked well on my aluminum boat. Used with a hand drill.

I got it to use when building speaker boxes, it works fine

The threaded hole for the center bit was tapped crooked. Completely unusable.

The yellow hole saw stripped in the mandrel in the first day of using. Metal too thin. Of no use to me after a hole or two cut.

Very happy with purchase. It saved a ton of time during the install of our basement lights. It was well worth the price when you factor in the time saved.

Never failed only used it 3 times yellow me later

the bit is not sharp it took an entire day to cut 1/16 plastic about half way through then we used a hammer to try and pop the bit out because it was stuck the the bit split into two pieces

Do not waste your time buying this. I bought to drill a hole in a new gas tank. It would not even cut through the tank before dulling. I had to go buy a better quality one to finish the job.

... or maybe a bit less. Being the cheapest 4 hole saw on Amazon, it clearly doesnt aim for quality, but it got my job done. Which was a neat and tidy 4 hole in my ceiling. It wobbled a bit; no big deal. And the arbor has no securing mechanism, neither locknut nor pins, so if you take your finger off the trigger suddenly to stop it, the saw flies off the arbor into hopefully vacant space. My advice is to screw it on as tightly as possible and slow the drill gradually.

Had everything I needed and worked perfectly. REALLY liked the spring that ejected the cut out plywood. Highly recommend this.