Clearance
Clearance is the difference between the space punch and die. X / 2 - half size of gap shown in Fig. 1.
Fig. 1. Clearance between punch and die.
Why is it important to choose the correct clearance?
Today made a lot of research in the field of metal, as a result of which found that clearance size directly affects the quality of the punched holes. So before you buy a set of punches and dies required to calculate its value.
If the gap is greater, then while punching forms a rough break with ragged burrs, from the die side, and the edge of the hole will have an extended appearance.
If the selected clearance is less than the allowable, then a cone rises to the top, it is also possible jam on the cut surface.
Choosing the right clearance ensures minimal deformation around the hole from the side of the punch, reduces the amount of burrs from the die side and increases tool life.
As a general rule, subject to the requirements of the selection tool, the die alignment, proper adjustment of the puller- punching tool is making about 10,000 holes.
Method of selection
In order to choose right clearance, it is necessary to know the thickness of the material. On the width of the gap also affects the form of metal.
Better to choose the value closest to the recommended minimum, since during operation the material wears out.
Standard clearances between punch and die:
| The thickness of the steel resistance 0,45, mm | Clearance, mm |
| From 1 to 3 | 0,2 |
| from 3 to 10 | 0,7 |
| from 10 to 14 | 1,2 |
| from 14 to 19 | 1,7 |
| from 20 | 2,2 |
Should be noted that the above table is not universal for all metals.
We want to help you choose the appropriate tool. If you have any questions, please call, we will be happy to answer them!