Silver zinc finish screws 20 x 4.8mm x 25mm with a shallow pan head, drill point self tapping thread for use with UPVC products. Bags of 20 are available. Because of its 4.8mm diameter gauge, this screw is usually referred to as an Upvc repair screw. Standard screws in the industry are typically between 3.9 and 4.3mm in diameter; consequently, by using the broader 4.8mm gauge, you may get a robust fastening point. Flat head with a countersunk hole.