prBAS ISO 230-12:2025

This document specifies methods for defining machining tests for manufacturing accurate test pieces, and for evaluating the influence of quasi-static geometric errors of linear axes and rotary axes, and the influence of the synchronization error of simultaneously controlled multiple axes. Although quasi-static geometric errors are often major contributors for geometric errors of finished test pieces, other factors, e.g. the dynamic contouring error, can also have significant influence. This document describes examples of test piece geometry applicable to individual machine tools, possible contributors to machining error, deviations to be measured and measuring instruments. By clarifying possible contributors to machining error in each machining test, this document gives a guidance to machine tool manufacturers or users such that proper machining tests can be chosen to evaluate a machine tool’s machining performance in specified machining applications. Machining tests to evaluate the geometric accuracy of a single surface are described in Clause 5, and those to evaluate geometric relationship of multiple machining features are described in Clause 6. Clause 7 presents machining tests for other objectives: machining tests for evaluation of short-term capability (7.2), and machining tests for evaluation of thermal influence (7.3).