The countersunk screws are very cheap metal that will break off in your project. I tightened them by hand and they still broke. I used three of these and after the second screw broke off I went and bought some better screws.
The write up on this item said super strong, the only thing I can say is WRONG. It's gripping strength was weak at best. If you are looking for something with a strong pull, I definitely recommend you find something other than this item