I bought these to mount on a workbench that I need to move around my basement workshop from time to time. Since other reviewers said the screws were of poor quality, I took great care in installing the casters. However, I had no problems with the screws. The main thing I did was drill the guide holes for the screws. I then used a hand screwdriver to screw them in place instead of a Phillips drill. I think it made a big difference. I used my own wrench, not the one that came with it, to install the lock washer and lug nut. Again no problem. As other reviewers have pointed out, there is a typo in the installation guide. The mounting plate should be 1 1/4" from the bottom of the leg, not 1.4" from the "knob". Bad translation. All in all pretty reliable if you use common sense when installing.