Pozi Screws, Reinforced Double Countersunk Head – Reduces head breakage and assists countersinking. Self Countersinking Ribs – For improved countersinking and a flush finish. Waxed Zinc and Yellow Passivated Finish – Corrosion resistant and significantly reduces torque. Milling Tread – Reduces torque, prevents splitting and torque. Serrated Thread – Cuts into wood reducing splitting and torque. Type 17 Cut Point – Reduces splitting and the requirement for pre-drilling. Each box comes complete with FREE pozi bit.