EH-500/500H Bakin Karfe M Haɗin gwiwa wanda aka yi amfani da shi don famfo don haɗi tare da bututu, ɗaukar rawar jiki da rage amo. Akwai nau'i biyu. Ɗayan nau'in walda ne, ɗayan kuma nau'in ba-welded ne. Don nau'in nau'in nau'in da ba a welded ba, ana yin gyare-gyaren wurin tuntuɓar ruwa tare da bellow ba tare da walƙiya ba. Kawar da lalata kayan walda.