discrete pressure - rupturable microcapsules for lubrication in powder metallurgy are disclosed comprising a core and a solid shell surrounding said core ; the core comprises an organic liquid lubricant able to wet powdered metals , the shell comprises a thin non - atmospherically degradable polymeric material ; the microcapsules may be used as the sole lubricant in the manufacture of sintered metal parts or may be used in admixture with unencapsulated solid lubricants to produce synergistic free - flowing compositions ; there are also provided novel compositions of matter for forming sintered metal components comprising a mixture of sinterable , powdered metal and the microcapsules .