Review on 🔪 Cutting Edge: CO Z Shank Cutter for Concrete Cement – Enhanced Performance and Efficiency by Loren Schmidt

I have used these hole saws with 8" concrete walls and 2" concrete blocks and Angelus blocks. It does a great job of cutting a nice clean hole as you can see in the attached photos and doesn't take much work with a good hole punch, especially with the smallest hole saw. The grinding surface of the crowns themselves looks like they will last forever. Even after drilling tons of holes I don't see any wear. The problem occurs when trying to change from one saw size to another. Unscrewing the hole saw from the shaft is almost impossible. For real ! You'll see in my photo that I had to fix one end in my desktop vise (thank goodness I have them!, the whole shaft, ugh) and then slide the tube over the vise handle to get the leverage needed to rotate . Wow! At the very least they should make sure the bar has a good flat surface so it can be gripped firmly when unscrewing it. nope It is circular up and down except for the critical end of the SDK. It takes me about 20 minutes to remove a saw hole of one size so I can attach another. That's why my star rating is less than 5. Ideally this should be with 3 rods and you don't need to change them at all - one for each size. If you want it to be one solid piece - the shaft and saw are all the same. Or you should be able to put the shank on and leave it there forever. Oh, and the grub screw holding the drill with the centering guide fell out immediately from all the vibration and was lost. You should provide a backup or two or come up with another method. I was lucky to find a threaded bolt at my shop that fits the hole.