According to the television manual it calls for M8 screws with a minimum 17mm, and maximum 22mm, of penetration into the television.

So you would use 8mm machine thread screws, that achieve that range of penetration, plus additional length for the thickness of the mount and any washers if recommended.

Wall mounts usually come with an assortment of screws in various sizes that usually will fit your needs.

ok, very good, thank you. much appreciated. Jim