POM, which has the advantages of high mechanical strength, high hardness, good wear resistance, can be used in cars instead of coppery half stalk and planet gear. It not only saving copper materials, but also improving service life; In electronic and electric Industries, such as: shell of electronic spanner,electronic scissors, coal drilling machine ,handle of switch, wireless recorder, video tape recorder, television, computer, electrograph, calculagraph, bracket of recorder tape and so on.