Sand core for casting

The utility model relates to a sand core for casting, and belongs to the casting field. The sand core comprises a sand core head, an upper casting mould and a lower casting mould, wherein the sand core head is in a cylinder structure with a through hole in the center; the two ends of the through hole in the center of the sand core head are machined into tapered cavities which expand from the inside to the outside; the lower end of the upper casting mould downwards extends with a tapered positioning boss which is matched with the inner shape of the tapered cavity at the upper end of the sand core head; the upper end of the lower casting mould is machined into a molded cavity with the outer edge inner diameter matched with the outer diameter of the cavity; the center of the molded cavity of the lower casting mould is serves as the tapered positioning boss which extends upwards and is matched with the tapered cavity at the lower end of the sand core head in the inner shape. The sand core for casting, disclosed by the utility model, improves the core setting accuracy, reduces the weight of the sand core head, lowers the height of a sand core box, facilitates the de-molding and improves the hardening of molded sand; meanwhile, the deformability and the knockability of the sand core head are improved.