Hot rolling blade material:5CrNiMo,5CrW2Si,6CrW2Si,3Cr2W8V,4Cr5MoSiV1(H13) This series of bit which is developed by our company , the life is above 3-5 times of the overall alloy tool steel bit , and may carry on the pre-protection and repair. In order to serve and supply you better products,we sincerely hope that you could afford such information as below:1)Detailed size or Dimension:Outer Diameter,Bore Diameter,Teeth Number,Thickness,Segment Size; 2)Segment Welding Methods:Laser,High frequncy,Hot press,Cold press 3) Base Body Materail: 9CrSi,Steel,or others 4) Your Quantity; 5) Your diagram;6) any other information you want to know.