Die Station 3: Restriking
In this example, Restriking is performed on the drawn form, because the selected material has a tensile yield strength that exceeds the value of the cost model variable matlYieldStrengthRestrikeThreshold (344.74 N/mm2 in starting point VPEs).
Restriking is also sometimes performed for a number of reasons besides material strength:
• Width-to-depth ratio: the form’s width-to-depth ratio is less than the cost model variable widthToDepthRestrikeThreshold (0.5 in starting point VPEs). The width-to-depth ratio is the SER Width divided by the sum of Depth Up and Depth Down.
• Depth-to-thickness ratio: the ratio of the form’s depth to the blank’s thickness is less than the cost model variable depthToMatlThicknessRestrikeThreshold (1000 in starting point VPEs). The depth-to-thickness ratio is the sum of Depth Up and Depth Down divided by the material thickness.
• Minimum radius of curvature: the form’s smallest radius of curvature is less than 10 times the blank thickness. You can customize the blank thickness multiplier (10 in starting point VPEs) with the cost model variable minRadiusOfCurvatureRestrikeThresholdMultiplier.
• Surface tolerance: the tolerance some surface of the form is tighter than the cost model variable minFormSurfaceToleranceRestrikeThreshold (0.5 in starting point VPEs).
Restriking can occur on the same die station along with multiple other operations, providied those operations are not perfomed on the surfaces being restruck and do not otherwise interfere with the restriking operation and tooling.