When the stainless steel pipe needs to change direction in the process of tooling layout, it needs to use stainless steel elbow connection, the Angle is 45º, 90º and so on.The commonly used method of stainless steel elbow forming production is push bending forming process.Push bending is a common method of bending stainless steel pipe fittings, mainly used for bending elbow.According to the characteristics of the process, it can be divided into cold push bending and hot push mandrel bending.
 

1.cold push bending
Using the bending device in the ordinary hydraulic press or crank press push tube blank technology method, at room temperature stainless steel straight tube blank is pressed into the mold with bending chamber, so as to form stainless steel elbow.Cold push elbow is suitable for stainless steel elbow with small bending radius, the relative bending radius R/D ≈ 1.3, the elbow section ellipticity is small (≤3%-5%), the outer tube wall thinning is small (≤9%) can be bent;The elbow pushing device is simple in structure, without special equipment and high productivity.However, it is generally required that the relative thickness of stainless steel pipe T/D ≥0.06, otherwise, the billet will often lose stability due to poor stiffness, resulting in wrinkling or distortion of the inside of the elbow.

2. mandrel hot push bending
Mandrel hot push bending tube is made on the pushing machine through the horn mandrel under axial thrust, while heating and pushing, so that the tube billet produces circumferential expansion and axial bending deformation, so that the tube billet with smaller diameter is pushed into larger diameter elbow.