1. Sand Casting making by: Mahmod abd elnabe 120072426

2.  Sand casting Is metal casting process characterized by using sand as the mold material. It is relatively cheap and sufficiently refractory even for steel foundry use.

3.  Basic process 1)Place a pattern in sand to create a mold. 2)Incorporate the pattern and sand in a gating system. 3)Remove the pattern. 4)Fill the mold cavity with molten metal. 5)Allow the metal to cool. 6)Break away the sand mold and remove the casting.  There are six steps in this process

4. Sands Silica sand (SiO2) Two general types of sand:  Naturally bonded (bank sand)  synthetic (lake sand)

5. Several factors affect the selection of sand for molds. Sand having fine, round grains can be closely packed and forms a smooth mold surface. Although fine-grained sand enhances mold strength, the fine grains also lower mold permeability Good permeability of molds and cores allows gases and steam evolved during casting to escape easily. The mold should have good collapsibility (to allow for the casting to shrink while cooling to avoid defects in the casting, such as hot tearing and cracking.

6. Types of Sand Molds  Green-sand. Is a mixture of sand, clay, and water  Cold-box. Various organic and inorganic binders are blended into the sand to bond the grains chemically for greater strength.  No-bake molds. A synthetic liquid resin is mixed with the sand; the mixture hardens at room temperature.