GB/T 244-2020 specifies the principles, equipment, test specimens, procedures, and test report requirements for the bend test of metallic tubes. It is applicable to the determination of the full-section bending plastic deformation capability of metallic tubes with circular cross-sections and an outer diameter not exceeding 65 mm. The test is generally conducted at a room temperature of 10℃ to 35℃, while tests with specific temperature requirements should be controlled at 23℃ ± 5℃. Instruments such as a tube bending machine, grooved bending dies, an angle gauge, and a projector are used to bend the specimen around a bending die of a specified radius to a designated angle. For longitudinally welded tubes, the position of the weld relative to the bending plane must be specified.