Industrial grade exothermic/ insulating sleeves are designed for efficient feeding of iron and steel castings. These sleeves are used as risers of iron and steel castings to help in directional solidification and in turn to achieve higher casting yields. These exothermic/ insulating sleeves exhibit low density and low thermal conductivity to minimise loss of heat from risers. Industrial grade exothermic/ insulating sleeves also exhibit toughess that helps it to withstand impact while ramming and jolting of the mould.