Tooling Terminology Glossary

Boot Core- A core used to form a casting feature away from the parting line. The boot is used to connect the core with the parting line to fix the core's position.

Cast Iron Corebox- Used for either hotbox processes or blow processes. Cast iron boxes are either cast from a master pattern and then polished, machined from a block of stock or both.

Core Strippers- Templates that strip the fins off a core after it is cured.

Core Setting Fixtures- Used to set several cores into a mold at once.

Coreboxes- Tooling used to form cores. Coreboxes for oilsand and cold box processes are usually made of wood or plastic. Because they are not heated and not under extreme abrasion, wood is usually sufficient. Often strike surfaces where the excess sand is struck away with a metal bar are coated with metal strips to enhance the life of the box. In processes where the boxes are heated metal must be used. Cast iron is the best choice for this. It is more wear resistant and dimensionally stable under heat. Aluminum, having a high coefficient of thermal expansion, tends to move too much when heat is applied. In core processes where sand is blown or injected into a box, it is good to use metal unless the quantities are low. The blowing is very abrasive and will wear out a wooden box very quickly.

Cover Cores- Cores used to form a complex shape in order to avoid using a matchplate.

Flatback- A mounted pattern that is not split because the shape is conducive to mounting a flat feature against the pattern board.

Follow-board- Used to help a molder make a part that would otherwise not lay flat against the split line. A follow-board follows the complex contour of a part.

Gauges (Gages)- Used to check castings for dimensional accuracy.

Paste Corebox- A paste box is used to make a portion of a core that will be pasted to one or more additional sections to form a whole assembly that can be placed in the mold.

Loose Pieces- Used in both molds and coreboxes to form an undercut. Loose pieces remain with the core or mold when it is drawn and are then removed. Loose pieces should be avoided when possible.

Loose pattern- One that is not mounted on a board. Often loose patterns are used in floor molding where a pattern is rammed up in the sand by hand on the floor.

Master patterns- Temporary patterns used as an intermediate step in making metal patterns or coreboxes. They are usually made of wood. A master pattern will have double shrinkage. Double shrinkage is necessary because the metal tooling will shrink once when it is cast and the casting will shrink a second time when it is cast.

Matchplates- Metal tooling that has been cast from a master with all of the impressions integrated into one, homogenous pattern. Usually made of aluminum although cast iron and bronze are sometimes used. Matchplates are necessary when the quantities to be made in the life of a part are high or when an offset parting line is required because of a complex configuration. A matchplate will last for many thousands of impressions.

Mold- A mold is what molten metal is poured into. It is not a pattern. See pattern.

Pattern- In the sand casting business tooling is commonly referred to as patterns and coreboxes. When sand is packed around it a pattern forms the cavity in the mold that will receive the metal. Patterns can be made of wood, metal, plastic or composites. Occasionally one will hear someone refer to a pattern as a mold. A mold is what the metal is poured into. It is not a pattern.

Patternmaker's Shrinkage- Before a patternmaker starts building a pattern he must calculate shrinkage. When metal cools from the point at which it became a solid to room temperature it contracts. Different metals contract at different rates. Ductile iron shrinks less than one sixteenth of an inch per foot. Stainless steel shrinks five sixteenths of an inch per foot. Most other metals shrink somewhere in between those extremes. To compensate for this, patternmakers have to make a pattern oversized. A table of shrinkage factors for various metals is provided at the end of the design section in this book.

Patternmaking- Patternmaking is a very old art. It goes back to the days of the guilds and artisans. Until recently patternmaking was learned as a trade. An aspiring patternmaker began as an apprentice, became a journeyman and, if good enough and persistent enough, became a master. There are very few masters left. Most of the new patternmakers come out of vocational schools today. The quality of the education is excellent. Patternmaking is very good profession for an individual with the necessary skills. It has become a technically oriented profession with today's computerized design and manufacturing methods.

Permanent Mold- A permanent mold is a metal or composite mold into which metal is poured directly. It will last for many cycles.

Plastic Pattern- Many patterns today are being made from composite materials. They are often referred to as plastic patterns. The most common plastic used is urethane although there are many. Often the resins are reinforced with glass or steel fibers to give the pattern more strength and wear resistance. Plastic is often a cost effective way to duplicate a shape. It is midway between wood and matchplates in both cost and durability.

Rigging- Rigging is the gates, runners, risers, traps, filters etc. that are designed by the foundry and built as part of a pattern.

Shell Corebox- A corebox used to make a shell core. It is a blow type box and normally is made of cast iron.

Shrink Rule- A special ruler used by patternmakers. It has linear (patternmaker's) shrinkage already calculated. A different shrink-rule is required for every increment of shrinkage.

Split Wood Pattern- Normally mounted with one half of the pattern on one side of a board and the other half on the other side.

Split Wood Corebox- A corebox split through a line from which a core can be drawn. The box is pinned to assure proper alignment and clamped together during filling.

Sweep Corebox- A somewhat crude method of forming a core by rotating a template about an axis to shave away sand in the shape desired.

Tooling- Foundry tooling includes all those pieces of equipment which are used in the manufacture of a specific casting. While patterns and coreboxes are the most common types of tooling, there are many others including core setting fixtures, core strippers, trim dies and gauges.

Trim Dies- Used to remove gating from the casting after it is shaken out.

Wood Patterns- The most common and most cost effective patterns are made of wood. They are usually durable enough to stand up for at least 1000 impressions and sometimes many more. Wood patterns are usually made of mahogany because of its tight grain, resistance to cracking, hardness and dimensional stability. A good patternmaker will glue together many pieces of wood to make a pattern in order to get the grain running the right direction for a given shape.
See also loose and split patterns.

Wood Corebox- A corebox made of wood.