Relates to ferrous and non-ferrous tapping and drive screws. It establishes type and shape varieties; dimensional proportions; standard diameters and lengths and their combinations; and covers materials, accuracy, finishes and quality. Information on the application of the various types and on sizes of labels for steel screws in a variety of materials is given in an appendix. A foreword discusses the reason for selection of the standard sizes and relates the standard range to the American and Canadian Standards.