Knowing the uncertainty result measurements of the trials is of a fundamental importance for the laboratories, their clients and for all the institutions which use these results in a comparative way. The competent laboratories know the performance of their methods of trying and the uncertainty associated with the measurement’s results. This work presents the working way which includes the steps that have to be taken to evaluate the uncertainty at the determination of the residual stress through the hole drilling method. Here are presented the concepts that are the basis of the measuring uncertainty evaluation, parameters for which uncertainty is to be estimated, sources of uncertainty and influence of factors on the measuring uncertainty of the hole drilling method and their quantification.
