Knowledge

To get the biggest bang for your buck, choose a minimum number of lower dies that will cover the entire range of metal thicknesses your shop forms. Shops with little tribal knowledge, unforeseen applications, and limited budgets should try selecting lower dies using the 8×2 rule. First, determine the range of metal thicknesses you want to bend. For example, you might need to bend material 0.030 in. through 0.250 in thick. Second, assess the smallest V die needed by multiplying the thinnest metal by 8. In this case, 0.030-in. material would need the smallest die, hence: 0.030 × 8 = 0.24, which we’ll round up to 0.25. Third, assess the largest V die needed by multiplying the thickest metal by 8. In this case, the thickest material of 0.250 in. would need the largest die: 0.250 × 8 = 2. You’ve now determined the smallest and largest die you need—0.25 and 2 in. To fill in what you need in between, you start with the smallest V die and double its size. In this case, that gives you a 0.5-in. die (0.25 × 2 = 0.5). Next, double the 0.5-in. die to get 1.0 in., then double that to get 2.0 in. This gives you a minimum of four different V-die openings to bend 0.030- to 0.250-in. material: 0.25, 0.5, 1.0, and 2.0 in.15:47:32

A maintenance shop will need and use different press brake tools than a custom fabricator will. So before diving into specifics, identify your needs and budgetary constraints. For instance, you might need additional tools to shorten setup times. You might follow lean manufacturing principles and recognize the benefits of having a separate tool library for each press brake—and hence, be willing to invest in duplicate sets of tools stored at machines. You don’t lose valuable setup time walking to and from the tool crib and elsewhere looking for the correct tools. An added benefit here is that tool style compatibility from machine to machine is no longer necessary, because the tools tend to stay with their intended machine (see Figure 3). If you need to buy additional, duplicate tools to expand each brake’s dedicated tool crib, choosing them is relatively straightforward. You’ll often find these tools located in convenient places, if not already in the press brakes. Look for the tools with the most wear and tear—those with shiny, bright working surfaces. The body of the tools will likely be clean and bright too. Rusty, dirty tools on the bottom of the rack are not likely candidates.

Self-retaining installation. You should be able to load the tools with the ram up. The toolholding system should hold multiple pieces in place until the clamping pressure is applied (see Figure 2). Self-seating. As clamping pressure is applied, the punches are mechanically pulled up into position. This eliminates the need to bottom the punch into the die during the setup. Front loading. You should be able to install tools from the front of the machine. This shortens setup time because you no longer need to spend time sliding tools from the end of the press brake. In most cases, front loading also eliminates the need for forklifts and overhead cranes. Standard sizes. Common-height tools can reduce the need for machine adjustments when changing jobs. Front support arms, backgauge heights, and safety devices all remain at a common position. And because tools are made to the same heights, you can add off-the-shelf pieces and be sure they will match your existing tools. Many high-quality press brake tools are made to metric standards. So a nominal sized 0.250-in. V opening is actually 6 mm, or 0.236 in. Moreover, bends in sheet metal have slightly elliptical corner radii, so you only have to get close to get correct. For simplicity, imperial dimensions are rounded in this article. Note that the discussion that follows focuses on air bending, and for good reason. The trend is to abandon bottoming or coining and embrace air bending whenever possible. Be aware, however, that not all parts can be produced using classic air bending techniques.   Operators throughout the industry use very different tooling to make parts of similar or identical quality. Plenty of operators make acceptable parts with incorrect tooling because they don’t have access to the correct tooling. They make it work; but “making it work” isn’t efficient or repeatable, and it can seriously hinder work flow. Best practices in tooling selection really should have one elegantly simple goal: to achieve the best-quality parts in the least amount of time possible.

Whether simple or complex parts – with our sheet metal bender, the highest repetition accuracy is guaranteed. Dynamic crowning and our patented Pressure-Reference technology ensure consistent quality.

What is the press brake mold made of? There are many types of materials available for manufacturing press brake tools, including steel, alloy materials, polymer materials, etc. At present, steel is the most widely used material for producing press brake molds, including T8 steel, T10 steel, 42CrMo, Cr12MoV, etc. 42CrMo is a high-strength alloy steel that exhibits high strength and toughness after quenching and tempering. It can work at low temperatures as low as -500 ° C and is known for its high strength, toughness, and wear resistance. The commonly used materials for press brake molds can be divided into eight categories. 1. Carbon tool steel T8A and T10A carbon tool steels are often used in the manufacturing of press brake molds due to their excellent machinability and cost-effectiveness. However, these materials have poor hardenability and red hardness, and significant deformation occurs during heat treatment. In addition, their load-bearing capacity is relatively low. 2. Low alloy tool steel Adding an appropriate amount of alloying elements to carbon tool steel produces low alloy tool steel, reducing the tendency for deformation and cracking during quenching, and improving the hardenability and wear resistance of the steel. Some low alloy steels commonly used in the production of press brake molds include CrWMn, 9Mn2V, 7CrSiMnMoV, and 6CrNiSiMnMoV. 3. High carbon and high chromium tool steel High carbon and high chromium tool steel is famous for its excellent hardenability, toughness, and wear resistance. During heat treatment, the deformation is minimal, making it a high wear-resistant steel with a load-bearing capacity second only to high-speed steel. However, due to the obvious segregation of carbides, repeated upsetting and drawing (axial upsetting and radial drawing) are required to reduce the unevenness of carbides and improve their performance. Some common high carbon and high chromium tool steels include Cr12, Cr12MoV, and Cr12MoV1. 4. High carbon medium chromium tool steel High carbon medium chromium tool steel used for press brake molds includes Cr4W2MoV, Cr6W, Cr5MoV, etc. These materials have low chromium content, fewer eutectic carbides, uniform distribution of carbides, minimal heat treatment deformation, good hardenability, and stable size. Compared with high carbon steel and high chromium steel with obvious carbide segregation, these materials have improved properties. 5. High speed steel High speed steel is commonly used in the production of press brake molds due to its high hardness, wear resistance, and compressive strength. It also has high load-bearing capacity. Commonly used are W18Cr4V, W6Mo5, and Cr4V2 to reduce tungsten, as well as 6W6Mo5 and Cr4v high-speed steels developed to enhance toughness. In order to improve the distribution of carbides, high-speed steel also needs to be forged. 6. Foundation steel Basic steel is produced by adding a small amount of other elements to high-speed steel and adjusting its carbon content to enhance its performance. Compared to high-speed steel, this can improve performance, such as increased wear resistance and hardness, as well as better fatigue strength and toughness. It is a high-strength and high toughness bending die steel, which is more cost-effective than high-speed steel. The commonly used basic steels for press brake molds include 6Cr4W3Mo2VNb, 7Cr7Mo2V2Si, 5Cr4Mo3SiMnVAL, etc. 7. Hard alloy and steel bonded hard alloy Hard alloy has the highest hardness and wear resistance in bending die steel, but its strength and toughness during bending are poor. Tungsten cobalt is used as a hard alloy in press brake molds. For bending molds that require low impact and high wear resistance, hard alloys with low cobalt content can be selected. For high impact molds, hard alloys with high cobalt content can be used. Steel bonded hard alloy is made by powder metallurgy using iron powder and a small amount of alloy element powder (such as chromium, molybdenum, tungsten, vanadium, etc.) as the binder, titanium carbide or tungsten carbide as the hard phase. The matrix of steel bonded hard alloy is steel, which solves the problems of poor toughness and difficult processing of hard alloy. This material can be cut, welded, forged, and heat treated. Steel bonded hard alloys contain many carbides, with lower hardness and wear resistance than hard alloys, but still higher than other steel grades. After quenching and tempering, its hardness can reach 68-73HRC. 8. New materials The material used for the press brake mold is a cold working mold steel, and its main performance requirements are strength, toughness, and wear resistance. At present, the development trend of press brake mold steel mainly has two directions, both centered around high alloy steel D2 (Cr12MoV). (1) Improving the toughness of bending molds, including reducing carbon content and alloy element content, and improving the uniformity of carbide distribution in steel. Examples in this direction include 8CrMo2V2Si and Cr8Mo2SiV. (2) Improve the wear resistance of press brake molds and adapt to the high-speed, automated, and mass production of powder high-speed steel. An example of this direction is 320CrVMo13.