Glossary of Casting Terms (R-Z)

Radiography – A non-destructive method of internal examination in which metal objects are exposed to a beam of X-ray or gamma radiation. Differences in thickness, density, or absorption, caused by internal defects of inclusions are apparent in the shadow image on fluorescent screen, or photographic film placed behind the object.

Rig – To prepare a pattern and flask equipment for molding.

Riser – A reservoir of molten metal provided to compensate for the contraction of the metal in a casting as it solidifies.

Runout – Casting defect caused by incomplete filling of the mold due to molten metal leaking or draining out of the mold.

Sag – A decrease in casting thickness caused by sagging of the cope or core.

Sand Tempering – Adding sufficient moisture to molding sand to make it workable.

Scab – A Defect on the surface of a casting which appears as a rough, slightly raised surface blemish, crusted over by a thin porous layer of metal under which is a honeycomb containing a layer of sand caused by spalling on the mold.

Tensile Strength –The maximum load intension which a material will withstand prior to fracture. It is calculated from the maximum load applied during the tensile test divided by the original cross-sectional area of the sample.

Veining – A defect on the surface of a casting appearing as veins or wrinkles and associated with excessive thermal movement of the sand, especially core sands.

Vent – A small opening or passage in a mold or core to facilitate escape of gases when the mold is poured.