Sheet metal bending dies are specialized tools used in press brakes to shape sheet metal into desired angles and forms, such as U-bends, V-bends, or complex profiles. These dies consist of a punch (upper die) and a die (lower die), which work together to apply force to the sheet metal, causing it to bend at a specific angle without fracturing. The design and material of bending dies are critical factors that determine the quality, accuracy, and efficiency of the bending process.

Bending dies are available in various types to accommodate different bending requirements. V-dies are the most common, with different groove widths to handle various sheet metal thicknesses and bend radii. Acute angle dies are used for creating sharp bends (less than 90 degrees), while radius dies produce rounded bends. Specialized dies, such as offset dies, hemming dies, and seaming dies, are designed for specific applications, such as creating flanges or joining two sheet metal parts.

The material of the dies depends on the type of sheet metal being bent and the production volume. High-carbon steel is often used for low to medium-volume production, while alloy steels (such as A2 or D2) with heat treatment are preferred for high-volume applications due to their increased wear resistance. For bending hard or thick materials (e.g., stainless steel or aluminum alloys), dies made from carbide or tool steel may be required to prevent premature wear.

Proper maintenance of bending dies is essential to ensure consistent performance. This includes cleaning dies after use to remove metal debris, inspecting for cracks or wear, and applying lubricant to reduce friction during bending. Regular sharpening or regrinding of worn dies helps maintain the accuracy of the bends. By selecting the right die type and material and maintaining them properly, manufacturers can achieve precise, repeatable bends in sheet metal fabrication.