An international testing exercise was conducted under ASTM Committee E10.02 to obtain a cross-comparison of material properties obtained from various types of subsize-specimen testing techniques. Sixteen organizations representing 10 countries initially participated in the exercise. Objectives were to (1) benchmark various subsize specimen testing techniques by comparing testing results with established material properties for the material tested, and (2) provide information to participants to improve the correlation of subsize specimen testing results with material properties determined through standard ASTM methods. The testing material for the cross-comparison exercise was the ASTM A533 grade B class 1 plate designated as HSST plate 03 provided by Oak Ridge National Laboratory. A variety of miniature testing techniques were utilized by the participants during this exercise. A summary of the exercise and a general comparison of the results obtained are provided. Detailed discussions on individual participant testing programs will be presented by each organization later in subsequent papers.