Coarse Thread Specialist Screw.Head: Countersunk Phillips Drive Bugle.Finish: Black Phosphate.Specialist Screws for drywall applications.Used for fitting plasterboard, fibreboard and other types of insulation boards to wood or steel studding-Phillips drive head.-Screws are made from fully hardened C1022 steel.-Extra deep insert bit recess offering a firmer positive drive.-Extremely sharp piercing point.-Thread gives speedy insertion and improved holding power.-Bugle head allows the screw to sink effortlessly into the dry lining without the need for countersinking.-Bugle head minimises damage to the surface enabling a smoother surface finish.-Phillips bit included with every box of 500 and 1000.-Predominantly used when fitting plasterboard to timber stud work.