Bi-Metal jigsaw blades are designed and manufactured for the professional user. Bi-metal blades last longer than high speed steel or carbon blades. Detail to the material used, tooth shape and sharpness make these blades cut clean, fast and have a longer life. Set includes: 48-42-5121, 48-42-5161, 48-42-5190 metal cutting blades, 48-42-5300, 48-42-5310 general purpose blades.