Fecha de publicación: 19/05/1910 Fuente: WIPO "pollen" 12,023. Pollen, A. H., [Mergenthaler Setzmaschinen-Fabrik Ges.]. May 21. Matrices for type-bar making machines are hardened by hammering the material throughout its area, or only at the part in which the formative cavity is to be punched. A row of matrix blanks a, Fig. 2, is passed through a hammering-mill g, of which the hammer face is adapted to produce the desired number of indentions e at the points to be occupied by the formative cavities. In a modification, the matrices are formed with projections which are hammered down flush with the edges, depressions being subsequently hammered in the edges if desired. According to another method, the strip h, Fig. 5, from which the matrix blanks are punched, has on one or both sides a ribf, which is hammered down.