This is for (100) pieces of Self Tapping Machine Screws Flat Head Type A Phillips. A self-tapping screw is a screw that can tap its own hole as it is driven into the material. Some self-tapping screws are also self-drilling, which means that, in addition to the tap-like flute in the leading threads, there is also a preliminary drill-like fluted tip that looks much like the tip of a center drill. These tapping screws feature a flat head that has a flat top and a taper. Flat heads are designed to be used in a countersunk hole. Sheet metal screws have sharp threads that cut into a material such as sheet metal, plastic or wood. They also make excellent fasteners for attaching metal hardware to wood. The fully threaded shank provides good retention in wood.Sheet metal screws are also the go-to fasteners when installing plastic wall anchors in drywall. They also make excellent fasteners for attaching metal hardware to wood. Tapping screws are considered externally threaded fasteners that "tap" their own mating threads. Tapping screws, especially Type A, are referred to as "sheet metal screws" because one of their first applications was in ventilation ducts made of sheet metal. Phillips drive is X-shaped for installation with a Phillips head screw driver. AISI 316 stainless is a premium grade of stainless and is considered by many to be best in class. 316 stainless is corrosion resistant and very durable even in the harshest of conditions.