Legor's OR135A is a master alloy for 375-585-750‰ (9-14-18 Kt) red gold jewelry, designed for mechanical working. OR135A is suitable for continuous casting and for ingot casting of semi-finished items such as sheet and wire.The main processes of 375-585-750‰ gold made using OR135A are massive chain, stamping, blanking and hand production. The color of 375-585-750‰ gold made using OR135A shows a red hue. MSDS. Technical Sheet.