3 Fundamentals of press design

4 Sheet metal forming and blanking
4.7 Fine blanking
In practice, fine blanking is also known by the terms precision blanking or
fine stamping. The production process involves shear blanking for the
manufacture of parts with a smooth cut surface. Like standard shear
blanking, according to DIN 8580 fine blanking falls under the main category
of material separation or parting processes, and is defined according
to DIN 8588 under the sub-category dividing (cf. Fig. 2.1.2). Compared to
standard shear blanking, also known as normal blanking (cf. Fig. 4.5.1),
however, different process parameters apply, resulting in a higher workpiece
quality.
The basic concept of fine blanking is that, in contrast to standard
blanking, the material is separated after being clamped on all sides
only as a result of material flow, i.e. without a fractured surface (cf.
Fig. 2.1.30).
4.7.1 Fine blanking process
Advantages of fine blanking
Apart from the quality-related advantages of fine blanking, cost-effectiveness
is also a decisive factor in favor of the application of this
process. Specific blank-related advantages compared to normal shear
blanking include:
– smooth blanked surfaces free from fracture and tearing which are
able to fulfil functions without the need for reworking,
– extended field of application for shear blanking,
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998