Method for creating openings in a base part and base part produced by the method

摘要

The method involves providing rim holes (5) for accommodating flat tubes with flanges. The rim holes are made by deformation of a base part (1) having a U-shaped cross-section, where the deformation is performed by wrench. The base part is made of solder-plated material e.g. solder-plated aluminum alloy, which partially covers collars. The rim holes are arranged in a middle part (4) of the base part. Narrow areas are formed as a trapezoidal projection.