SHANGHAI, Aug. 19 (SMM)--SHFE lead prices opened lower then edged up, but failed to boost domestic spot lead prices. Well-known brands such as Nanfang and Chihong Zn & Ge were generally quoted between RMB 16,180-16,200/mt, with discounts of negative RMB 350-400/mt against SHFE 1110 lead contract prices. Other brands such as Jinguan and Tianma were mostly quoted between RMB 16,050-16,100/mt. Downstream buyers increased purchases at lower prices, causing transactions to improve from yesterday.