What is the best method and fastener for attaching cabinets to drywall covered steel studs?
(Cabinet and Millwork Installation Forum)
From contributor D:
I use #10 x 2-1/2" wood screw at 3 per stud with 2 in the top and 1 in the bottom for the uppers. I use 2 in the top to insure that at least one really does grab. I have never had trouble with cabinets that I have installed myself this way but I have had to go back and install toggle bolts on some cabinets that have let go recently that were installed by employees.
I think that they over tightened the screws and stripped them out. I prefer wood backing but it's not allowed in many buildings these days. A lot of architects are specifying 16 Ga. sheet steel backing. I find that this doesn’t work very well because the screws just push it out of the way so you still have to hit a stud.
You only want to screw through the sheetrock and into the metal stud - not the cabinet. Make sure you hold tight against the wall and set your clutch so you don’t strip the hold in the metal. Also, I would glue them with Pl 300 ,400,500, even liquid nails.
I like the point about using the fine thread screws for attaching to studs, but not a drywall screw. Make sure to use a screw with a shank diameter designed to carry the load of the cabinet and its contents - drywall screws are not. I'm sure Baer Supply and all other fastener companies carry a fine thread wood screw to do the job.