The black oxide finish steel sheet metal screw with serrated hex washer head and slotted drive has a Type AB point for forming threads in thin metals between 0.015" and 0.050" thick and resin impregnated plywood. The Type AB point has the conical tip of a Type A point with the finer spaced threads of a Type B point. Steel is often used in applications where strength is the primary consideration. The black oxide finish offers mild corrosion resistance and lubricity. The hex washer head has six flat sides that a wrench can grip to turn from the side, enabling use when there is no space above the head for a screwdriver. The serrated flange acts like a washer to increase the fastener's bearing surface and distribute the clamping force over a larger area, providing a grip that resists loosening. The slotted drive has a linear slot for use with a flat-blade driver.Sheet metal screws, a type of self-tapping screw, have threads down the entire length of the shank for tapping and fastening thin material. The point style determines the type of material the screw can be used on, such as metal, wood, or plastic. These screws commonly have a sharp point that helps penetrate the material.