This specification establishes the requirements for externally threaded fasteners of diameters from .30 UNM (.0118 in.) to 1.40 UNM (.0551 in.) inclusive@ which fall within the classification of Miniature Screws and which are designed to be assembled with tapped holes or nuts and driven by means of a jeweler's type screwdriver. There is only one class of thread established: this is with zero allowance on all diameters. All tolerances governing limits of size are based on functions of the pitch only and apply to lengths of engagement from two-thirds to one and one-half times the nominal diameter.