Deep Drawing Die Design: Key Principles

Introduction

Deep drawing is a complex sheet metal forming process. Proper die design is essential to produce defect-free parts. This article covers the fundamental principles of deep drawing die design.

Draw Radius

The die draw radius should be approximately 5 to 10 times the material thickness. Too small a radius causes tearing. Too large a radius causes wrinkling. The punch radius should be slightly smaller than the die radius.

Die Clearance

Clearance between punch and die is typically 10 to 20 percent greater than material thickness. Proper clearance ensures clean material flow without excessive thinning or excessive force.

Blank Holder Force

The blank holder prevents wrinkling by applying pressure to the flange area. Too little force causes wrinkles. Too much force causes tearing. The correct force depends on material, thickness, and draw depth.

Carbide Die Surfaces

Polished carbide surfaces are essential for deep drawing. They reduce friction, prevent galling, and enable smooth material flow. The draw radius and entry angle must be highly polished.

Multi-Stage Drawing

Deep, complex parts may require multiple drawing stages. Each stage reduces the part diameter gradually. Intermediate annealing may be required for materials that work-harden quickly.

Conclusion

Successful deep drawing die design balances draw radius, clearance, blank holder force, and surface finish. Using carbide dies with polished surfaces significantly improves results and die life.

References

GB/T 7714: GUPTA R, SONG J. Powder metallurgy processing and mechanical properties of cemented tungsten carbide composites[J]. International Journal of Refractory Metals and Hard Materials, 2020, 91: 105246.

APA 7th: Gupta, R., & Song, J. (2020). Powder metallurgy processing and mechanical properties of cemented tungsten carbide composites.

MLA 9th: Gupta, R., and J. Song. "Powder Metallurgy Processing and Mechanical Properties of Cemented Tungsten Carbide Composites."