The K-factor in sheet metal working is a crucial variable that directly influences bending accuracy. In practice, it indicates the relative position of the so-called ‘neutral fibre’ in relation to the total thickness. The ‘neutral fibre’ is that plane where the structure of the sheet metal remains unformed; the further inwards we move, the more the metal is compressed. Conversely, on the outside it will undergo elongation. This coefficient takes into account the characteristics of the material and the bending process. Its calculation is essential to accurately predict how much the sheet metal will stretch during bending.
The calculation of the K-factor involves several parameters, including sheet thickness, inner bend radius and bend angle. The basic formula is:
This coefficient customises the bending compensation formula, allowing more accurate results. A correct value of K is essential to avoid errors in the final dimensions of the folded sheet.
Bend allowance is a critical element in sheet metal fabrication, crucial for achieving accurate bends and meeting design specifications. Its calculation requires attention to several parameters, including the flat length of the sheet, the length of the two bent sides, the sheet thickness and the internal bend radius.
The basic formula for calculating the Bend Allowance is:
In this equation, the flat length of the sheet is implicitly taken as the sum of the lengths of the two bent sides. The term π/180 converts the bending angle from degrees to radians.
Accurately measuring the flat length, folded sides, sheet thickness and inner radius is critical for an accurate Bend Allowance calculation. This parameter, together with the K-Factor, customises the formula to suit the specifics of the material and bending process.
In conclusion, the calculation of Bend Allowance is an essential step in sheet metal working. A correct understanding and application of this formula ensures that bends conform to the desired dimensions, thus contributing to the production of high quality components.
