1, the processing error can be eliminated, mainly to eliminate processing errors, because the process is not up to the 100% of accuracy; 2, can be sure killed when verticality, Fay is not glue if it is easy to make the Guide bushing crowded narrow, tight vertical distribution is not guaranteed; 3. to reduce the cost. Requirements for dowel hole lower mould wire cutting, guide bushes, if using glue, you can change the wire for the high speed wire processing, this is especially suitable for small stamping plant. 4, inner guide bushing plastic irrigation can insure good cutting clearance.