Sheet metal blanking: the importance of the clearance between the mould and punch

Written in Processes on
principale - Tranciatura lamiere l’importanza del gioco tra matrice e punzone

Only in-depth machining process knowledge can allow sheet metal blanking machines to always guarantee the best clearance between the mould and punch: to too high and not too low.

To professionally blank sheet metal it is essential for machines to be calibrated to guarantee the right clearance between the mould and punch: only if the dimensions of the mould and those of the punch permit the optimal motion of the two parts, then the obtained part will be free of defects and the machine protected against premature wear.

Let's take a look together:

  • What are the most common defects due to imperfect blanking
  • What are the benefits provided by perfectly calibrated blanking machines
  • What are the possibilities tied to Minifaber blanking service.


Blanking defects when clearance is not calibrated

Sheet metal blanking defects are produced by too high or too low clearance:

  • When the clearance between the mould and punch is too high, the excessive space between the two parts causes the edges of the sheet metal to curve, bend and product excessive burrs.
  • When, on the other hand, the clearance is too low and the space between the two parts is too short, contact between the mould and punch causes rapid machine wear; worn parts inevitably produce semi-finished or finishes parts with irregular and sharp edges.

How do you check whether clearance was correctly calculated?

Simple: just check that the breaks on the upper and lower edge of the blanked sheet metal are on the same line.


The benefits of appropriate clearance

Appropriate clearance between the mould and punch thus allows the two parts to meet on a single trajectory, creating clean and precise edges. But these are not the only benefits:

  • No conical edges (drawing)
  • Minimum burrs
  • The press exerts minimum force
  • The mould lasts longer.


Sheet metal blanking with Minifaber

Thanks to the experience accumulated over years of work in the sheet metal processing sector, Minifaber can offer you professional sheet metal blanking service: accurately calculating the clearance between the mould and punch and adapting it to different thicknesses and materials, we are able to always produce semi-finished and finished parts with even and clean edges, ready to be used in a wide variety of sectors (electromechanics, medial, robotics, etc.)

Our machine fleet is made up of 17 mechanical press and 1 on-board cleaning system: we blank iron, stainless steel, aluminum, copper and the main special alloy sheet metals such as brass.


Do you want to learn more about the possibilities offered by Minifaber sheet metal blanking service? Contact us!
Angela Melocchi
author Angela Melocchi
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