Abstract: A method of manufacture of a hollow stabilizer for automobiles which uses a heat-finished seamless steel pipe 20 as a material, comprising an inner surface and/or an outer surface of a part corresponding to a bending R portion A-B of the steel pipe 20 is polished to remove defects of the surface of the steel pipe, and after the above surface roughness is made less than Rmax 50 .mu.m, the part corresponding to the above bending R portion is previously formed an ellipse in section, and then the section after bending process accesses to a true circle to alleviate stress concentration of the bending part.

Abstract: A stabilizer used for vehicles and the like is formed integral with a base, shoulders on both sides of the base, and arms each formed with an eye-termination provided at the free end thereof for connecting the stabilizer to a load, said arms being each partly provided in separation from the remaining part of the stabilizer and welded to the latter at a predetermined position thereof the weld position satisfying a condition for maintaining sufficient strength of the stabilizer, to thereby produce the stabilizer more easily with a reduction in cost as well as to heighten the spring property thereof.

Abstract: A bar-shaped torsion spring, such as a torsion bar or a stabilizer. The spring is made with a hollow interior main body. Linking mechanisms and fixing portions are formed integral with or connected to both ends of the main body of the spring. A cover of reinforced plastics is applied to the outer circumference of the main body of the spring.

Abstract: A method of forming a taper leaf for use in a laminated spring wherein pre-tapering work is first performed by which a terminal portion of a sheet of spring material is transformed in its lateral direction so as to become thinner toward the tip while maintaining the vertical thickness of the sheet or section at the original thickness of the material. Subsequently, the same portion is rolled for tapering in a vertical direction.