3.9 x 38mm Window Fabrication Screws – Countersunk with Ribs – PH – Self-Tapping Thread – Self-Drilling Point – Martensitic Stainless Steel & Silver Organic

Multiple uses for fitting a variety of hardware to frames where there is a steel or aluminium reinforcement present. Stainless steel should be used where there is a corrosive environment. Countersunk head with ribs under head for improved countersinking.