The following table summarizes the advantages and disadvantages of the different classes of pattern equipment used by metal casters.
|Wood Loose||Low cost to produce. Use to produce plastic patterns. Easily modified.||Not suitable for production batches unless converted into plastic before becoming worn. Tend to become inaccurate and to produce poor surface finish.|
|Hardwood||Inexpensive for small-batch production. Can be used as masters for plastic patterns. Fairly easily modified but expensive if multiple impressions involved.||Fair wearing properties. With care, will remain reasonably accurate over fairly long periods. Not suitable for high-volume production.|
|Plastic||Inexpensive to produce. Urethane technology provides good wearing properties and accuracy. Easily modified depending upon the materials used. Suitable for high-volume production patterns with the same dimensional tolerances as metal patterns.||Urethane technology has reduced many of the disadvantages of early plastic pattern materials.|
|Metal||Excellent wearing properties. High standard of accuracy and stability. Suitable for high-volume production and shell molding. CAD/CAM improvements are greatly reducing cost and lead time requirements.||Costly. Difficult to modify. Equipment is less adaptable for movement from one foundry to another.|