Copyright Goodheart-Willcox Co., Inc. 26 Section 1 Introduction to Drafting and Print Reading Goodheart-Willcox Publisher Figure 2‑12. Single-stroke Gothic lettering, usually set in uppercase letters, is the established standard for engineering drawings. Summary • A convention is a generally accepted way of doing things. • The list of ASME standard lines is referred to as the alphabet of lines. • Standard practices recommend two thicknesses for linework in industrial prints: thick (0.6 mm) and thin (0.3 mm). • The visible line can be described as a thick and continuous line used to show the outline and shape of the part. • The hidden line can be described as thin, black, short, closely spaced dashes used to describe hidden features of the object in a particular view. • The center line can be described as a series of thin, black dashes, alternating between medium and long, used to show symmetry, identify center axes, or describe paths of motion. • Lines used in dimensioning are drawn black, thin, and continuous, including extension lines that extend the shape from the view, and dimension lines that include arrows on each end to show the extent and direction of the dimension. • Leader lines, drawn thin and black, feature an arrow on one end and a shoulder on the other end, most often in association with a lettered note. • Lines used in sectional views include section lines, which are thin and black and usually appear in a pattern of angled lines sometimes called hatching, with the possibility of dashes to identify particular materials. • Cutting-plane lines and viewing-plane lines may be drawn in one of three options, all of which include elbows and arrows to express the direction for viewing. • Break lines are available in “long break” and “short break” options and are used when drawings or views need to show longer lengths or hidden features in a conventional manner. • The alphabet of lines includes several miscellaneous types of lines such as the phantom line, stitch line, and chain line, each with a recommended dash pattern and line weight. • The style of lettering recommended for standard industrial drawings is uppercase single-stroke Gothic lettering, indicating a clear, sans-serif form of lettering that is easy to read.