The production and use of castings involves several main categories of players, with a significant amount of overlap. We felt it would help people use this site more efficiently if we identified five main areas of activity within the supply chain:

• Castings are what this site is all about, and so the manufacture of castings from hot metal is the common thread in all the different supply arrangements that can be used to obtain cast metal parts.
• Patterns and/or tools are used in every casting. A critically important issue, however, is that some manufacturers make their own patterns/tools, some buy them from outside suppliers, and some do both. Moreover, some produce patterns/tools for both their own use and for sale to other manufacturers of castings. An additional issue is that buyer of the final casting is usually the legal owner of the pattern/tool, and plays a role in its procurement.
• Post-finishing involves issues similar to those with patterns/tools: some castings manufacturers do their own post-finishing, while others contract outside shops to do that work.
• Buying castings: it can be seen from the foregoing that every purchase of castings always includes the purchase of the casting itself as well as a pattern/tool, and often includes the purchase of post-finishing as well! A single end-user might purchase all three from a single vendor, or from three different vendors; there are many other possible combinations in-between. A firm that is a vendor of one or more of these services may also be a buyer of others in the course of his operations.
• Inputs include machinery, metals & other consumables, test equipment, software, services, etc., for use by firms that make castings, make patterns/tools, and/or do post-finishing. They are not used or owned directly by the final users of the cast metal part

We know that many of you participate in more than one of the above elements of the supply chain, and we hope the structure of the CastingTrade.com site will make it as easy as possible for you to do your work in each.

END-USE SEGMENTS: Why do we categorize the market for cast metal parts in these four main groups?

Data on castings production is often broken down into a dozen or more user areas. Sometimes this makes it hard "to see the forest for the trees." We felt it would be useful to try to identify a small handful of distinctly different segments, and have arrived at a segmentation scheme we believe best combines the virtues of simplicity and specificity. It divides the market for cast metal parts into the following four segments:

• Auto is a unique because of the massive scale of the principal companies involved, and the high level of organization of their requirements. (This segment also includes internal combustion engines for use in non-consumer trucks, which admittedly share certain features with the equipment segment.)
• Fittings and municipal is unique because it is the major area of castings that involves many standardized parts used by many customers, rather than involving custom parts for every different customer.
• The equipment segment involves parts. (This segment also includes castings for certain high-volume consumer appliances, which admittedly share certain features with the auto segment.)
• The specialty segment includes metal parts that are characterized by at least two of the following characteristics: extremely high tolerances, unusual alloys, short runs, and government procurement

CASTING PROCESSES: Why do we divide metal casting processes into these four categories?

Our categories for castings processes are based on issues of principal concern and convenience to buyers of cast metal parts. This makes our system of categories slightly different than those adopted by the foundry associations, such as the American Foundrymen's Society, because those tend to be based on production logic that is, naturally, of primary importance to the manufacturer but may be of only secondary importance to the buyer.

We felt it would be useful to try to identify a small handful of distinctly different process categories, and have arrived at a scheme we believe best combines the virtues of simplicity and specificity. It divides the processes used to produce cast metal parts into the following four groups:

• Sand casting is the basic casting process. A major characteristic is that it has easy-to-comprehend limitations on geometry, and low tooling costs counterpoised against throughput limitations. There are also finish limitations. (A significant number of advanced forms of sand casting enhance the geometries and finish qualities achievable, and make tradeoffs in the tooling/setup vs. throughput efficiency equation. It must be noted that there are finite limits to what can be achieved in each area, however.)
• Diecasting is a distinct contrast to sand casting. It utilizes very expensive tools, but also achieves very high throughput efficiencies.
• Investment casting is a unique and wonderful technology. It has a tooling/setup/throughput structure like sandcasting, only moreso. Its distinguishing characteristic is the ability to create parts with an internal geometry and/or articulation in three different planes. It achieves this through an ingenious, though initially difficult to understand, process of "investment" of an expendable center inside a crust.
• "Semi-Permanent/Other" refers to casting in which the molds are made of a refractory (i.e. ceramic) material and can be used for extended production runs. Technically, diecasting is a form of "permanent casting. However, for reasons described above, we have chosen to place it in its own separate category