Required stress area
12.3
Fig. 1
Punch fastening
AS Stress area fastening Fab stripper forceAfter the stripper force has applied, the fastening screws should retain a residual preload. In toolmaking, bolts are calculated according to the stripper force, but a safety factor of 6 is used.32
Eqn. 1
| Stress area | AS | > | mm2 |
| Safety factor | v | = | ||||
| Yield strength | σy | = | MPa | |||
| Stripper force | Fab | = | kN |
Calc 1
If standard bolts with quality class 8.8 are used, the yield strength of the screw material is 640 MPa.
32
Kolbe, M.; Hellwig, W. / Spanlose Fertigung Stanzen / Springer Vieweg / Wiesbaden / 2015 / 11. Auflage