| 摘要 |
PURPOSE:To improve the machinability and workability of a mold by adding small amounts of Fe and P to the brass material. CONSTITUTION:The compsn. of the titled material is made up of, by weight, <=3.0% Fe and/or <=1.0% P, 58.0-72.0% Cu and the balance Zn with ordinary impurities. The ordinary impurities involve Pb, Sn, Ni, etc., and it is permissible, if the total weight thereof amounts to <=0.1%. The generation of chatters and burrs at the time of groove cutting can be prevented and the accuracy of molded lens, screen, etc., can be improved when said material is used as the mold for molding of the resinous lens, screen, etc. |
