A screw, usually not more than 1/4 inch in diameter, with a machine-cut thread in tapped holes in metal parts. Standardized thread profile is 60-degree thread angle with round crest and trough.
Specification, Thread Profile, Internal Thread, External Thread, Axial Line of Screw Thread, ANSI Machine Screw, UNC (Unified National Coarse), TPI (Threads per inch), Pitch, Major Dia., UNF (Unified National Fine), Metric Course Machine Screw