In the present document, the results obtained when testing metal specimens in traction in a constructed prototype are described and the data compared with those obtained with the same procedure in a properly calibrated machine. Test pieces of aluminum, copper, bronze brass and aluminum steel were tested. , in accordance with the ASTM E8 / E8M regulation. In the failure process, five specimens were used for each material, both in the prototype and in the properly calibrated machine. The percentages of maximum forces, failure force, maximum stress and failure stress of the specimens were calculated and compared between the two machines and it was determined that the prototype and the calibrated machine reach similarity values between 92% and 94%. Based on the results obtained, it is concluded that the prototype is a good alternative as a support instrument in laboratory tests in the Materials Mechanics subject.