Abstract: This paper has analysed the experimental results of transverse rupture strength of YG 15 hardmetals by mathematical method. The principle and method for estimating general strength distribution by using the results obtained from a limited quantity of specimens were discribed and the physical significance on parameters of distribution characteristics was discussed. It has been found that the left value of strength confidence intervals both contains the average value of experimental results and refects deviation level which can illustrate the strength level of alloys reliablely and can be used as the data for evaluating the strength properties of materials. Meanwhile, the strength data can be used to effectively reveal the effects of HIP on the strength of hardmetals.