Sand core and manufacturing method

The invention discloses a sand core and a manufacturing method, and relates to the technical field of sand cores, the sand core comprises a core bar, the two sides of the core bar are fixedly connected with first steel bars, the first steel bars extend to the two ends of the core bar in the axial direction, the outer side of each first steel bar is fixedly provided with a plurality of second steel bars at intervals in the axial direction, and the second steel bars extend to the two ends of the core bar. The first steel bars extend outwards in the radial direction, the second steel bars extend outwards in the radial direction, the overall structure of the core bar, the first steel bars and the second steel bars is wrapped with sand bodies, the sand bodies wrapped outside the second steel bars and the core bar and the sand bodies wrapped at the two ends of the first steel bars form core heads, and air outlet ropes are pre-buried in the core heads. According to the sand core and the manufacturing method, the str