The main characteristics of the mold:
The mould is applied to high-chromium ball/strip cast, with sandbox interchanged freely. The sand mould has many strong points of simple operation, full utilization of molten iron, high-yield, shapely appearance, no shrinkage cavity and porosity. As well as, it can meet other materials’ cast.

• Heating: it should be heated before using. When in 200 ℃ to 300 ℃ around, the die will be casted. 
• Building: after heated, the upper and lower dies should be poured with sand (Note: Jiangxi sand is the best). A hole is need in the middle of sand mould with a tube as the inlet of molten iron after the upper mould finished.
• paint: after the sand-mould finished, the ball bowl of mould should be protected with acetylene through spray smoke (Note: it need protected after sand-mould finished every time)
• Casting: The mould should be closed after protection, and then immit the molten iron through the inlet pipe until full. 
• Open mould: we should open the mould with two round bars respectively insert the holes on it, and get the balls out, then re-mould and re-cast.
• sand ratio: 100 kg sand equipped with 20 kg clay and 8~12 kg water glass, and then put them into milling machines to crush down.