Regulation 71

The bending test-pieces shall withstand being bent, without fracture, through an angle of 180°. The internal radius of the bend shall not be greater than that specified in the following table:Maximum specified tensile strength of forgingInternal radius of testing piece after bending inchUp to 32 tons per square inch1/4Above 32 tons and up to 36 tons per square inch3/8Above 36 tons and up to 40 tons per square inch5/8