Recently, automotive parts uses move resin products or pipe-like products in order to achieve high quality or light weight. Additionally, the shape of automotive parts becomes more complicated. The rotary stretch bending method, although it is most popular method of bending a pipe, has some problems, such as a bending radius is limited due to use of bending mold, a thickness of an outer side of a bending portion is thinner, and a product is scratched easily during manufacturing. We have developed a three dimensional pipe bending process using a floating expanding plug and confirmed that this method can solve the above problems. 2 refs., 9 figs., 3 tabs.