Abstract
In this report, the mass effect on the pressing force in Shore hardness test was investigated. The experiment was carried out with a Shore scleroscope of D-type on five specimens which were different in hardness and in material. It need scarcely be mentioned that the general requests for testing were satisfied in this experiment. Especially operating conditions of the tester were maintained constant mechanically throughout this experiment. As a result, the mass effect on the pressing force was made clear. That is, the effect of the pressing force on the hardness number is influenced by weight of the specimen, and disappear in the specimen whose weight is greater than the critical weight. It has been revealed that the critical weight has been decided according to the hardness of specimen. And the critical pressing force has varied according to the weight of specimen. And, the critical pressing force curves shown in the second report, were modified in this report in the light of the mass effect.