Drywall Black Phosphate Coarse Thread Drywall Screws are specialist screws for drywall wall applications, used for fitting plasterboard, fibreboard and other types of insulation boards to wood or steel studding. Advantages of Forgefix Black Phosphate Coarse Thread Drywall Screws 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. Predominantly used when fitting plasterboard to timber stud work. Phillips bit included with every box of 500 and 1000. Dimensions Size: M4.2 x 100mmFinish: Black PhosphateBox Qty: 500