The term 'PART OF SOME HAMMERS' refers to three different components of a hammer. The first is the peen, which is the flat end of the hammer head that is used for riveting and shaping metal. The second is the CLAW, which is the curved end of the hammer head that is used for pulling out nails. The third is the ballpeen, which is a type of hammer head that has a round end that is used for striking and shaping metal.