Glossary of Casting Terminology "R"
This glossary lists in alphabetical order casting industry terms and their explanations.
| Word/Expression | Explanation |
|---|---|
| ram cylinder | A cylinder that operates under hydraulic pressure only for pushing actions and an item's own weight or a spring, etc., for pulling actions. It is simple in design, can apply substantial hydraulic force and a large rod diameter specifically for the clamping direction—such as with a press—gives it good rigidity. |
| reamer | A cutting tool used for finishing a drilled hole during machining. In casting, it is used for deburring the cast piece. |
| relay circuit | An electric circuit using an electromagnetic relay with contacts. This type of circuit's high contact rating and resistance to noise has seen it often used in various kinds of electric circuits (e.g. motor control circuit), but with the prevalence of sequencers, they are less commonly used as electric circuits today. |
| renewal mold | A mold made after the original has deteriorated through repeated use (shots) and reached the end of its life. |
| residual stress | The stress existing inside a casting after it cools to room temperature following heat treatment or due to the difference in the linear thermal expansion coefficients, etc., of the casting and mold during solidification. |
| resin coated sand | Created by hot-coating silica sand with phenol resin, hexamine, calcium stearate, etc., and then cooling it. Often abbreviated to RCS. |
| return scrap | Refers to materials besides the finished piece that can be melted down for reuse or recycling after the casting process, such as gates, risers and defective castings. |
| reverberatory furnace | A type of melting furnace in which flames are generated with a fuel (e.g., coal, heavy oil or gas) and the resulting heat is reflected by the furnace ceiling in order to heat and melt a material. |
| reversing device | A device for inverting objects such as molds and cast products. Some are used by an operator but others use hydraulic pressure or electric motors for handling items large in size. |
| rheocasting | A semi-solid casting method in which a molten metal, e.g., aluminum alloy, is cooled while stirring it to produce fine grains from the primary crystals. The work is formed when a prescribed solid phase rate is reached. |
| rib | Plate-shaped sections positioned perpendicularly on the cast material's flat or thinner areas in order to reinforce them. |
| rigidity | A property of a casting to resist external forces applied to cause deformation. |
| rim | The peripheral portion of a circular object such as a vehicle wheel. |
| riser | With iron casting or gravity casting of aluminum in particular, as the molten metal for the casting begins to solidify within the mold, portions within the final product's form may have insufficient metal due to solidification shrinkage and thus require additional molten metal be supplied. A riser is a molten metal reservoir set up above the casting to provide this extra metal to the areas lacking. |
| rolled tap (forming tap) | A type of screw threading formed by using the plasticity of a metal to shape it into the threads without cutting. Machining a female thread by cutting into the metal is called a “cutting tap.” |
| run | The process of the mold being filled with molten metal and forming the shape of the desired casting. |
| runner | Part of the casting design, a runner is a passage that allows the poured molten metal to gently and smoothly flow toward the mold cavity for forming the casting. |
| rust | Corroded material (e.g., oxides or hydroxides) resulting from the oxidation of unstable metallic atoms on the surface of a casting or the machined surface of a casting due to the presence of oxygen, moisture or the like. |
| rustproof | Preventing a metal from rusting. Examples of this include surface treatments like painting or plating, coating with oil, or wrapping with anti-rust paper or packing material. |
