... requirements 4. High quality Feature:Material: Iron, self-smelting according to standard: ASTM, EN, DIN, ISO, JIS, GB, etc;Sand ... mold casting: Iron casting, through sodium silicated-bonded sand and/or resin sand;Non-destructive examination: -visual detection;-Ultrasonic test ;- ... EN, DIN, ISO, JIS, GB Machining tolerance: unless otherwise according to dwg or requirement; big size elbow casting