The Red Book is a comprehensive technical handbook covering detailed specifications, material properties, and die design theory. The Black Book (“Example of Design Principles”) is an illustrated guide focused on practical application, showing “Do’s and Don’ts” for blanking, piercing, and forming to reduce manufacturing costs.

Key blanking rules include: Avoid sharp corners (use a minimum radius of 0.5x material thickness), ensure minimum feature widths are at least 2x material thickness, and design tabs/notches to be wide enough to prevent tooling breakage. The Black Book provides visual examples of these conditions.

 A general rule for mild steel is that the hole diameter should not be less than 1.2x the material thickness. For higher tensile materials like stainless steel, the minimum diameter should be 2x the material thickness.

To prevent distortion, the distance from the edge of a hole to the beginning of a bend should be at least 1.5x the material thickness (plus the bend radius). If the design requires a closer hole, a secondary operation or relief cut may be needed—techniques detailed in our design guide.

The minimum inside bend radius is typically 1x material thickness (1t) for ductile materials like soft steel and aluminum. Harder materials or those with specific grain directions may require a larger radius (e.g., 2t-4t) to avoid fracturing.