In lost-wax casting, a core pin or refractory spacing block connecting the core placed within a wax model to its surrounding mold. There are often many employed for each work, and may vary in size from thin wire to thick bars of metal, depending on the scale of the model. When the wax is melted from the mold, the chaplets keep the core from shifting. When molten metal is poured in, they are incorporated into it, and when the investment is broken off, they protrude from the surface of the metal. When they are made of the same alloy as the cast, they are difficult to find once they have been filed down. If they fall out when the core is removed, they leave holes which must be filled.