Stahlschmidt & Flender GmbH
Aherhammer 3-9
D-57223 Kreuztal
Tel. +49 (0) 27 32 / 58 53 - 0
Fax +49 (0) 27 32 / 2 75 44
E-Mail: info@aherhammer.de
Technical Standards
3. Squareness of cut plates
Squareness deviation limits for specific sheet thicknesses.
| Thickness [s] |
Maximum deviation [u] |
|---|---|
| <= 3 mm | 0,2 mm je 100 mm Kantenlänge |
| > 3 mm | 0,4 mm je 100 mm Kantenlänge |
Picture 2: Deviation u of squareness
The deviation of squareness is the rectangular projection of a horizontal edge on to a vertical edge.
Parallelism
During the process of perforating, stretch occurs in the perforated area. The amount of stretch is dependent on a number of factors, i. e. hole size, pattern, grade and type of material, material thickness etc.
Due to the considerable number of variables, it is not practical to set tolerances for the amount of stretch that might take place. After perforation and during the flattening operation the stretch in turn creates distortion over the perforated area, especially when side and end margins are present.
Picture (3) shows an exaggerated view of the type of problem that can be experienced. The full lines show the profile of material and the perforated area. The broken lines show the profiles after flattening. This profile can, of course, alter considerably depending on the previously mentioned factors and so may not be symmetrical along the centre line.
Picture 3
Picture 4
When material has been cut to size as shown in picture 4, the "out of square" problem can be seen, i. e. edge of perforated area not running parallel to the edge of the component.
If it is considered essential that the sides and ends of the perforated area should run parallel to the edge of the component, the customer is advised to contact the manufacturer prior to placing an order to discuss any possible problems which may arise.