When sheet metal is bend, the inside bending surface is compressed. The formula for calculating sheet metal bending allowance is (Please refer to the above picture): BA= Bend Angle * (Π/180)* (R+ K factor* T)……Eqn.1. Inside Through the Material (ISTM) – The distance between the outside and inside mold lines. A big driver behind this is the use of the term “minimum bend radius” on many drawings, and how that term is interpreted. A Sharp bend will always be less than a Minimum bend radius but, a Minimum Bend radius does not need to be sharp.. R is inner bend radius. Minimum Bend Radius Whereas the outer surface is stretched. As a result, overall sheet length increases. Here again, a “Minimum Bend Radius” is not necessarily the same thing as a “Sharp bend. In above bend allowance formula, except Sheet metal k-factor and bend allowance values. Input material thickness and and inner radius to get the data of K factor, Y factor, neutral layer. a cutout or the edge of your flange) to your bend. Finally, use formula (1) to calculate the bending force: If the usually recommended formula is used to calculate the bending force: From P1/P2 = 1.5, it can be seen that the difference between the two is … A k-factor average of 0.4468 is used for most bending applications. Bend Angle represents the angle to which sheet metal has bend (here it is 90 degree). Where. To ascertain your K-Factor, inside radius, and material thickness (expressed as a decimal), you should use an Bend Allowance Chart. Choose your thickness. radius, metal will crack at the outside heel of the bend. This calculator predicts what the minimum bend radius should be to avoid chacking or orange peeling on the outside radius of the bend. R = Inside Bend Radius; A = Bending Angle; T = Sheet Thickness; K = Value of K-Factor. When bends are made smaller than the required min. radius of a bend is determined by the hardness and thickness of the metal. Mathematically Bend allowance during Sheet metal bending can be calculated as: Bend Allowance (BA) = (Π/180) × ( R + K×T) × A. This change in sheet length depends on the position of neutral axis or k-factor. Then input the bend angle to get the arc length, bend allowance and bend deduction. Determine your minimum bend by measuring the distance from your closest feature (i.e. The lowest common bench capacity is around 100 tonnes. The min. Many see “minimum bend radius” and reach for the sharpest punch they have, the … Therefore, even a simple bench with enough room to bend 3 m pieces will do the job. All other values are known to the user. Sheet thickness (in): Die edge radius (in): Punch edge radius (in): Bend length (in): Ultimate tensile strength (psi): Factor of safety: Then input leg length A and B to get the flat size of the sheet. K-factor Calculator for Sheet Metal Bending. If you have any questions or want to discuss your design, contact us. Where, BA is Bend allowance. Inside Offset (ISOS) – Distance between the inside mold lines and the bend line. When calculating the outside offset use the included bend angle. My workpiece’s bending line is 3 m, so the overall needed force is 3*22=66 tonnes. The required die width is 12 mm and tonnage per meter is 22. Choose your material. Choose a Bend Radius that matches your Minimum Bend. The length of the neutral axis is calculated as a bend allowance, taken at 50 percent of the material thickness. As an example, if you want to bend 24 gauge sheet metal at a 90° angle, the calculation would be: 0.017453 x 90 x (0.020 … bend radius. BA = [ (0.017453 × Inside radius) + (0.0078 × Material thickness)] × Bend angle, which is always complementary. The most important considerations when bending metal is the min. Inside Shift (ISS) – Distance between the …