stretching technology is extremely complex. we should consider the following important factors in practice.
material selection
1, different materials with different tensile properties. the limit of elongation( the ratio of the diameter of blank and stamping). stainless steel is controlled at 2.1 to 2.2 and carbon steel is controlled at 2.15 to 2.5. the stainless steel material can be pulled deep again after deep drawing, but unlike the carbon steel material, the stainless steel material can not normally be stretched at the same degree as the first, unless heat treated. stainless steel materials require equipment power is 1 to 2 times than carbon steel equipment. in general, the double-action hydraulic equipment for deep drawing is the best.
lubricants selection
2, for the lubricants, we should consider two factors. the good lubricants should provide oil film to prevent scratches and reduce friction. also it is able to clear easily and thoroughly after the deep drawing. it may include chlorinated or sulfurized fats or waxes, heavy emulsions, or deep-drawn soap.
