Critical notes and considerations on the use of ISO 286-1 for CAD modelling and rapid product development

摘要

International Standard Organisation (ISO) system of limits and fits used in linear tolerancing is published in relevant international standards and recommended for use worldwide. Due to ambiguity in these standards, in some cases the data and the technical terms given in the standard may be misinterpreted especially when used in automated Computer Aided Design (CAD) modelling systems. The objective of this research work is to clarify the procedure of determination of the fundamental deviation of a tolerance. This is necessary as to radically improve the product development cycle by reducing the modelling time. In this paper, a new universal formula for the calculation of the correction A, which supersedes some numerical data from the standard that could be potentially misused are presented. Some amendments related to the key technical terms have been offered to bring agility to the linear tolerancing.