I bought these shorter legs to replace the longer legs for my elderly mothers tempurpedic ergo base(about 10 years old). I was hoping the m8 to m10 bolts would work, but m10 was still too small. However I wrapped a rubber band around the threads and that worked. Probably the best thing to do is find the right size adapter screw (maybe a M12?) and go wirth that, but this hack seems to work fine. Legs seem like they are good quality.