When multiple bends are on the same plane try and design the part so the bends all face the same direction. We again highly recommend that you don't do this manually, and that you use sheet metal-capable CAD software instead. The problems most of the manufacturers face while making a sheet metal part is the size of sheet metal. Welding by hand should be restricted to gauges thicker than 20 gauge. Hems are used to create folds in sheet metal in order to stiffen edges and create an edge safe to touch. Avoid large parts when possible, and especially large parts with small or detailed flanges. What is Bend Allowance and Outside Setback? Know the tools available in your shop or the standards if you are outsourcing production. Because the material will stretch during the bend, the total length of the part - including the radiused area where the bend takes place - will be larger than the original flat pattern defined. Recommended Minimum distance between two hole centers in sheet metal design should be equal to sum of hole radius plus two times the sheet thickness. From a bend, dimples should be at least 2 times material thickness plus the dimple radius plus the bend radius. If you are creating a flat pattern manually, you will either need to compute bend deductions, or use our app to obtain bend deduction and other information for your bend. For selected bends, our system will report the bend radius, bend allowance, bend deduction, outside setback, and k-factor. However for typical parts meant to be cost effective and easily produced the following tips should be useful. We do not currently have gooseneck punches or extensions to allow for deep, narrow channels, although we will expand our tooling options over time. Or the inside radius of the dimple plus 3 times material thickness. When you design your part in CAD, you can configure both the bend radius and k-factor to match our manufacturing processes, so that your finished part is as close as possible to the size you intend. At OSH Cut, we publish the bend radius that will be formed using our material and tooling in our material catalog. From bend to extruded hole, distance should be 3 times material thickness plus bend radius. Embossments and offsets should be measured to the same side of material unless it is necessary to hold an outside dimension. But if the finished size of your part is important, we highly recommend that you use CAD software so that you are certain that your flat pattern and bend locations produce the part that you need. These should be used as general guidelines, and may not cover all cases. Combined with the material bend radius, the k-factor allows the computer to figure out exactly how your part will stretch during bending. For holes, the minimum distance between the hole’s edge is 2 times the material thickness plus the hem’s radius. The distance between two countersinks should be kept to at least 8 times the material thickness. Somewhere in the middle, the material does neither: the length of that region is the bend allowance length. - 3 - Embosses and Offsets – Emboss and offset dimensions should be to the same side of the material unless the overall height is critical. In a bent sheet-metal part, the Bend Radius is the radius of the bent metal where the punch meets the part. During a bend, the outside of the material stretches, and the inside compresses. In a part produced using air bending, the metal is placed between a punch and a V-die as shown below: As the press brake forces the punch and the die together, the metal folds where the punch makes contact with the part. Like Bend Deductions, Bend Allowance and Outside Setback can help you manually modify a flat pattern to obtain the correct finished part size. Sheet Metal Fabrication Resources, Blog and Discussion Forum. For V embossments the maximum depth is equal to 3 times material thickness. Wire material should always be the same as the material being welded. The part itself only touches the punch on the bend line, and the v … This will create an opening with a 1 material thickness radius. Below, we walk through how bending works, and how to understand the design rules published in our catalog. 1) Use common metal materials to reduce material specifications and control as much as possible within the company’s material manual; 2) In the same product, reduce the variety of materials and sheet thickness specifications … These holes will also give you control over how the part is positioned when it is dipped. This is negated if the blank is being cut by a. A hole should be at least three times material thickness away from the edge of the dimple. Usually, you don't use k-factor directly. Embossments should be at least 3 times material thickness from a hole’s edge. The profiles for our available punches currently match what is shown above. Maximum flange heights for the above materials are given below: contains design rules for each bending material that we offer. Between two parallel ribs, minimum distance is 10 times material thickness plus the radius of the ribs.