SHANGHAI, May 15 (SMM) - The overall stainless steel prices moved with some declines on poor demand even though spot arrivals in the market decreased, hence the mills' real-time profit margins gradually approached the break-even point. Some mills that produced goods mainly for warrant delivery were more cautious in restocking raw materials to control their costs. The cost of the RKEF process stood at around 15,838 yuan/mt, and that of the non-RKEF process was about 16,020 yuan/mt. SHFE nickel prices edged lower last week amid the constant decline in CPI and bearish news as well as negative macro factors. The NPI prices grew owing to its supply tightness and the intensive purchases by stainless steel mills. However, the stainless steel scrap prices dropped due to the expanding supply. Ferrochrome prices ran stably. In general, costs of stainless steel dropped last week, but the spot stainless steel prices fell faster. The mills planned to ramp up their production intensively in May, which will weigh heavily on the spot prices. Therefore, the profits of stainless steel mills will shrink further this week.