Machine Screws, also referred to as Machine Bolts, are often used with nuts or driven into tapped holes. They come in a variety of head types and drive styles, but are generally available in smaller sizes.
Nylon 6/6 is a general purpose thermoplastic with outstanding resistance to organic chemicals, acids and alkalis. Nylon wears well against other surfaces; it is readily machinable and may be milled, turned and cut with conventional machine tools. It does exhibit some dimensional swelling in wet applications which should be taken into account with its use. Tensile strength of this material is 12,000 psi (pounds per square inch).
Fillister head fasteners are considered an improvement over round head equivalents - the smaller head creates more downward pressure for a given torque level and the thicker head plus deeper drive slot allows higher torque levels to be generated. The Phillips drive style was originally designed so that the driver would slip out under extreme torque, preventing over-tightening and damage to the fastener or the material.
A threaded fastener's size name includes information about the major external diameter, followed by the threads per inch, which indicates if it is coarse or fine.