I did not install these rails as they did not come with screws. I checked all the packaging and each pair of slides that were packaged together and no screws. As a result, I never installed them and sent them back. Upon inspection they appear to be made the same way as all other full extension slides I have used. These are the first of many slides I've purchased that didn't come with mounting screws, so I just assumed they did. If you take the time to read the fine print on a web page, you'll find "no screws" in parentheses.