A solid pattern is a model of the part as a single piece. It is the easiest to fabricate but can cause some difficulties in making the mold. The parting line and runner system must be determined separately. Solid patterns are typically used for geometrically simple parts that are produced in low quantities.
A split pattern models the part as two separate pieces that meet along the parting line of the mold. Using two separate pieces allows the mold cavities in the cope and drag to be made separately, the parting line being already determined. Split patterns are typically used for parts that are geometrically complex and are produced in moderate quantities.
Match Plate Pattern
A match-plate pattern is similar to a split pattern, except that each half of the pattern is attached to opposite sides of a single plate. The plate is usually made from wood or metal. This pattern design ensures proper alignment of the mold cavities in the cope and drag, and the runner system can be included on the match plate. Match-plate patterns are used for larger production quantities and are often used when the process is automated.
Cope and Drag Pattern
Cope and drag patterns are similar to match plate patterns, except that each half of the pattern is attached to a separate plate and the mold halves are made independently. Just as with a match plate pattern, the plates ensure proper alignment of the mold cavities in the cope and drag. The runner system can be included on the plates. Cope and drag patterns are often desirable for larger castings, where a match-plate pattern would be too heavy and cumbersome. They are also used for larger production quantities and are, again, often used when the process is automated.