A built-in sink unit with at least one basin, which has first surface areas, such as the bottom of the basin, subject to severe wear during use as well as second surface areas, such as the side walls of the basin, subject to less severe wear during use and in which the first surface areas are provided with a three-dimensional surface structure and the second surface areas are smooth. To ensure that any surface damage in the region of the surface areas subject to severe wear during use does not immediately catch the eye, the built-in sink unit gives the optical impression, when new, of really being a new article and the sink unit can, finally, be cleaned effectively with abrasive means without any disadvantageous optical effects thereby resulting, the surface structure of the first areas is formed by microgrooves at least approximately straight and extending parallel to one another, the surface roughness measured transversely to the longitudinal direction of the microgrooves being greater than 0.1 .mu.m and at the most approximately 0.4 .mu.m.

Shipping container carrying cargoes requiring temperature control and/or ventilation require a main frame capable of housing a refrigeration unit. Hitherto, main frames have been constructed by welding the component parts together which is extremely time consuming. The present invention provides a method for producing a main frame in which a recessed portion for housing the refrigeration unit is deep drawn while a force is simultaneously applied to maintain a substantially constant thickness of the main frame.

A method and apparatus are disclosed for forming a drawn container pan having planar side walls and smooth curved corner walls the upper edges of which are formed with an outwardly directed peripheral stacker ledge and an upstanding rim, and wherein the pan is formed by drawing the peripheral edge of a blank between clamping surfaces under selected pressure differential at the portions of the blank forming the side and corner walls of the pan. A method and apparatus are also disclosed for trimming the drawn pan and forming stacking protuberances adjacent the corners of the pan.

A method of drawing metal cups from metal sheets, which includes the steps of separating non-circular blanks of material from a metal sheet and of drawing cups from such blanks. The blanks may be of substantially hexagonal or square shape.

A method for forming a stainless steel sink bowl having a top edge, a sidewall and a bottom surface interconnected by smooth corner surfaces from a single sheet is provided. The method comprises drawing a stainless steel blank between a first draw die and a first forming die to form a first drawn blank having an unfinished bowl with a length, width and depth which are less than the finished length and width and generating a deformation warmth in the blank at the corner surfaces in proximity to the rim as the first drawn blank is being formed to a temperature of approximately 70.degree. C. to 90.degree. C. The first drawn blank is immediately removed from the first draw die and the first forming die and transferred to a finish draw die. The first drawn blank is finish drawn, prior to loss of the deformation warmth, between the finish draw die and a finish forming die to form a finish drawn blank having a finished bowl while simultaneously forming a grid ledge at a medial position in a portion of the sidewall of the finished bowl. A stainless steel sink bowl formed from a single sheet of material and having a grid ledge is also provided.