TS 3993

TS 3993 is a standard concerned with the control-function symbols used on numerically controlled machine tools. In practical terms, it supports a common visual language for panels, programming environments, and technical documentation, so the same machine function can be read and understood consistently. Symbols replace or complement text with compact graphical signs, which is especially useful where controls must be recognized quickly and unambiguously.

What control symbols do in CNC environments

In general technical use, symbols for numerical control represent machine actions or states such as motion directions, cycle start and stop, or other operating functions. This kind of graphic notation helps reduce ambiguity in human-machine communication and is valuable on complex, automated machine tools where many commands must be distinguished at a glance. The broader purpose is consistency: one symbol should convey the same operational idea across documents, interfaces, and equipment.

Document boundary and technical focus

The standard covers symbols for numerical control of machines and is published as equivalent to ISO 2972:1979. That means its focus is the graphic representation of control functions, not the performance of the machine tool itself. As a result, the document belongs to the family of graphical-symbol standards that support clearer operation, interpretation, and documentation in industrial equipment.

• Graphical symbols for control functions
• Use on numerically controlled machine tools
• Consistent interpretation in documentation and interfaces
• Based on an international symbol standard