It comes down to four factors: the machine, the tooling, the lubricant, and the tube material.
Knowing the characteristics of the tube or pipe you’re working with is the first step in bending. Pipe is defined by its nominal pipe size and is often used to transfer liquids or air (see Figure 1). Nevertheless, the centerline radius, outer diameter, and wall thickness are important factors to consider when specifying a bending machine.
Every schedule of pipes also has a specified wall thickness. There is a tolerance, and there may be a small variation in wall thickness. Particularly for bending procedures utilizing exact, snug-fitting tooling on short bend radii, this difference should be taken into consideration.
Additional bending parameters include the midline radius or neutral line, where neither compression nor stretching occurs, the inner bend radius (also known as the intrados), the outer bend radius (or extrados), and others. The bend angle is the bend’s complementary angle. Hence, if a tube is bent “45 degrees,” it means that the bend angle is 135 degrees plus 45 degrees (see Figure 2). The DBB stands for the distance between bends. More specifically, it’s the distance between two tangent points, or the beginning and end of a bend on a straight stretch of line.
Similar to press brake forming, after bending tubes encounter springback, resulting in a bend that develops radially. In general, the springback and subsequent radial expansion are stronger the harder the tube and the smaller the centerline radius of the bend. Stainless steel has less springback than regular steel, which has less radial growth than copper.
Similar to press brake forming, after bending tubes encounter springback, resulting in a bend that develops radially. In general, the springback and subsequent radial expansion are stronger the harder the tube and the smaller the centerline radius of the bend. Stainless steel has less springback than regular steel, which has less radial growth than copper.
