Torx 6 Lobe Pan Head Machine Screws
Black Oxide 18-8 Stainless Steel
UNC and UNF sizes available ranging from #2-56 to #10-32. Torx head machine screws are often used with nuts as well as driven into tapped holes. In practice, they tend to be mostly available in smaller sizes and the smaller sizes are referred to as screws, or less ambiguously as machine screws, although some kinds of machine screw can be referred to as stove bolts.
Torx, or 6 Lobe drive styles have become very widespread. The main cause of this trend is manufacturing efficiency: Torx and other types are designed so the driver will not slip out of the fastener as will a Phillips drive, since the driver is not inherently centered on the fastener.) A benefit/disadvantage of non-typical fasteners (depending on your point of view) is that it can be more difficult for users of a device to disassemble it than if more-common head types were used, but Torx and other drivers are widely available.
Machine Screws in 18-8 Stainless Steel offer the fastener industry standard of corrosion resistance, making the screw more durable, and suitable for harsh environments. Black Oxide Screws are Phillips head screws that have been chemically treated to alter certain qualities of the material, most notably the color. The treatment also adds a mild corrosion and abrasion resistance (in addition to the plain stainless steelís nature), and reduces the now black oxide stainless steel fastenerís reflective properties. To achieve maximum corrosion and abrasion resistance, the black oxide is infused with wax or oil during the process and complies with military specifications as a Class 4 finish.
Fasteners that have been treated in this manner are commonly used in the automotive industry on both car and motorcycle builds. Additionally, this type of fastener finish is often used in gun and knife builds, particularly in the handles, because of its corrosion and abrasion resistant qualities. Of course, black oxide fasteners are also used for their sleek black look as well.