each group of magnetic material absorbability is fixed  while the excluding volume could be changed according to the conveying speed and the distance between each magnetic material group .magnetizer's broken pieces scrpas and flour whose length is shorter than 50mm are mainly conveyed .they are widely used in such cutting and chopping machine as numerical control macine combined machine production line process used combined with other form of scraps excluding requirement if there are cooling oil the conveying result could be sesigned and made according to the cutting and chopping machine's difference