Transactions of The Electrochemical Society · 1933 · 15 citations · 0 references
The authors refer briefly to the historical developments of hard materials for the arts. Five methods of determining hardness of materials which exceed the range of the ordinary testing machines are described. The usefulness and limitation of each is discussed. One of these methods involves the use of a new machine which measures a type of impact abrasion hardness. Full details are given. A complete description of the nature of the samples used for comparison is included. Significant results obtained by each method are tabulated to show a comparative scale of hardness. Some conclusions are made as to the relative hardness of electrochemical products in relation to Moh's scale. An extension of Moh's scale is suggested.