Sand core for casting rear arm cast of vehicle

The utility model relates to a sand core for casting a rear arm cast of a vehicle. The sand core includes a vehicle rear arm sand core body, a vehicle rear arm sand core torsion bar arranged at one end of the vehicle rear arm sand core body, and a vehicle rear arm sand core pin arranged at the other end of the vehicle rear arm sand core body, wherein a chilled iron bar is embedded into the vehicle rear arm sand core torsion bar, and penetrates the vehicle rear arm sand core torsion bar in the axial direction of the vehicle rear arm sand core torsion bar. Since the chilled iron bar is arranged in the vehicle rear arm sand core torsion bar, the problem of dispersed shrinkage of inner shrinkage holes of the vehicle rear arm cast produced by the sand core can be obviously solved, and the chilled iron core can also enhance the strength of the vehicle rear arm sand core, the damage of the vehicle rear arm sand core during transportation is reduced, and the work efficiency is improved.