Type U Drive Screws, Drive Screws, U Drive Screws, also known as Hammer Drive Screw are un-slotted round head self-tapping screw used for making permanent fastenings in metal, plastics, and wood, such as securing nameplates in castings. They require a pre-drilled hole and can be installed with a hammer. The hole size should be slightly smaller than the shank diameter. They may be mildly magnetic.
18-8 Stainless Steel
The number 18-8 refer to the percentages of chromium and nickel in the stainless steel Alloy. The 18 refers to the chromium content, which provides rust-resistance properties, and the 8 refers to the nickel content, which gives a silver-like shine and some rust-resistance. 18-8 is probably the most commonly used stainless steel.
Round Head | ANSI/ASME B18.6.2