Easydrive Black Bugle Head Coarse Thread Uncollated Drywall Screws 3.5 x 38mm 1000 Pack (52220)

Hello, Thank you for using Q&A. Coarse threads are more resistant to stripping and cross threading because they have greater flank engagement. Coarse threads install much faster as they require fewer turns per unit length. Finer threads are stronger as they have a larger stress area for the same diameter thread, so it depends on your application i.e. courser threads are ideal for fixing plasterboard. Hope that helps. MH

Hello, These screws are designed for Plasterboard so have not been tested for use on end-grain, therefore we cannot guarantee its performance if used in end-grain. Generally for screwing into end grain you would use a dowel or insert nut. There may be some screws that are more suited to end grain, but you may wish to check with a competent trade person which you should use (there are other factors which need to be accounted for i.e the thickness of the plywood, weight applications etc. Thanks for using Q&A. [DG].

Hello phoenix2, these are only used for For fixing plasterboard to timber partitions. thank you for using Q and A.JB

Hello This product is not suitable for fixing timber to steel joist. Thanks for using Q&A