TS 2040 ISO 1302

TS 2040 ISO 1302 is a standard for technical drawings that defines how surface texture is indicated, combining graphical symbols with supplementary information. This matters because a drawing must communicate not only a part’s geometry but also the expected surface character after machining, grinding, casting, coating, or other finishing processes.

Core ideas behind surface texture indication

Surface texture indication is used to express characteristics such as roughness, waviness, and lay on a drawing. In general technical practice, these markings create a common language between design, manufacturing, and inspection so that a surface is understood not only as “to be machined” or “not to be machined,” but also, when needed, with additional notes about the intended surface condition. Based on ISO 1302:1992, this standard focuses on the symbols and additional indications used on technical drawings.

Why the notation matters in engineering documentation

Surface texture can affect fit, friction, sealing, appearance, and repeatability, which is why it must be communicated clearly on drawings. The framework provided by this standard helps different industries read the same surface symbols in the same way. TS 2040 ISO 1302 was published on the basis of ISO 1302:1992 and is intended to be used together with related terminology and surface-parameter standards, so that surface information remains consistent within the broader dimensioning and tolerancing structure of the drawing.