Many shearing, blanking, and piercing operations are based on the same underlying principles of shear mechanisms. This article provides information on the various operations associated with die cutting and describes three phases involved in the shear cutting or punching action. These phases include deformation, penetration and fracture. The article also explains the effect of clearance on tool life and force and power requirements. It reviews the forces involved in the punching process and describes the diameter of a hole or blank in relation to material thickness. The limitations of punching are also discussed. The article describes the relationship of the die clearance to stress-strain curves and explains the procedure of interpreting the stress-strain curves. The article concludes with information on the dynamic stripping forces in blanking.

This article illustrates the characteristics of pierced holes and summarizes the hole wall quality. Specific guidance in selecting die clearances is provided by considering the types of edges produced with different clearances. The article discusses the effect of tool dulling and the use of small and large clearance. It informs that the force needed to pierce a given material depends on the shear strength of the work metal, the peripheral size of the hole or holes to be pierced, stock thickness, and depth of shear on the punch. The article discusses the presses and tools used in piercing. It illustrates the use of compound dies, progressive dies, and transfer dies; piercing of thick and thin stock and piercing holes at an angle to the surface; special piercing techniques; and shaving of low-carbon steels.

This article illustrates the mechanics of the deep drawing of a cylindrical cup. It discusses the fundamentals of drawing and drawability. Sheet metal is drawn in either hydraulic or mechanical presses. The article summarizes the defects in drawing and factors considered in press selection for drawing. It explains the types of dies used for drawing sheet metal and the effects of process variables and material variables on deep drawing. The process variables that affect the success or failure of a deep-drawing operation include the punch and die radii, punch-to-die clearance, press speed, lubrication, and type of restraint of metal flow used. The article describes the process of redrawing and ironing of metals. Drawing of workpieces with flanges and drawing of hemispheres are also illustrated. The article also provides information on the reducing of drawn shells, methods for expanding portions of drawn workpieces, trimming, and deep drawing using fluid-forming presses.

This article discusses the presses, auxiliary equipment, and dies used in the blanking and piercing of commonly used magnetically soft materials, namely, low-carbon electrical steels and oriented and nonoriented silicon electrical steels. It describes the effect of stock thickness and work metal composition and condition on blanking and piercing. The article provides an overview of the influence of burr height on stacking factors and presents a discussion on the lubrication and core plating of electrical steels that ease the process.