The Hillman Group 3990 M4-0.70 x 20mm Metric Stainless Steel Pan Head Phillips Machine Screw (15-Pack) Machine screws are fully threaded along the shaft Fasten with a screwdriver to reduce the risk of over-tightening to protect the screw and fastened material Use for any indoor/outdoor projects Stainless steels are used for their corrosion resistance, high-temperature strength, scaling resistance and low-temperature toughness