1,15years professional manufacture 2,bi-metal hole saw 3,cutting wood,steel 4:size14~380mm 5:export ... high speed steel and spring steel;3.Adopt imbalanced scale-saw and lateral teeth design,with characteristics of rapid trepan ... 55mm)34mm (specification56~220mm)Matching drill: Electric drill/percussion drill(rotating mode)ModeDiameterModeDiametermillimeter (mm)inchmillimeter (mm)inchS1-14149/16"S1- ...