Precision Metalworkers

Tool, die, and mold makers are among the most highly skilled production workers in the economy. They possess a broad knowledge of machining operations, can read complex blueprints, and are able to do complicated mathematical calculations. They may produce many different kinds of devices or they may specialize in just one item. In a small shop, a single worker is typically responsible for all the steps necessary to complete a device from start to finish, while in a larger shop, specialized production tasks are allocated among several workers, with the tool maker or die maker acting as a job supervisor.

Many types of machine shops and workers are covered under the tool and die category. They include tool and die shops that produce dies, punches, die sets and components, sub-presses, jigs and fixtures, and special checking devices. Also included are companies that manufacture molds for die-casting and foundry casting, and shops that make metal molds for plastics, rubber, plaster, and glass working.

In general, pressworking dies are used to cut and shape sheet metals with electrical or hydraulic presses. Composed of two units, the upper part attaches to a press ram and the lower part attaches to a press bed. Molding dies, used to form both metals and plastics, consist of two units which when closed form a cavity into which molten material is poured.

No matter what the shop produces, however, when a job first arrives, the tool and die makers must analyze instructions, blueprints, sketches, or models of the finished product. Using such information, they decide how to go about making the device. After the dimensions are computed, the tool and die makers plan the layout and assembly processes and decide on a sequence of operations for machining the metal.

When the plan is clear, workers select and lay out metal stock, measuring and marking the metal, and if necessary, cutting it into pieces of the approximate size needed for the project. They set up the machine tools, such as lathes, drill presses, and grinders, and carefully cut, bore, and drill the metal according to their predetermined plan. In the machining process, they closely monitor the dimensions of the workpiece since their work must have a high degree of accuracy—frequently within ten-thousandths of an inch. Measuring equipment, such as micrometers, gauge blocks, and dial indicators, is used to ensure precision.

When satisfied that the parts are accurately machined in accordance with the original specifications, tool and die makers fit the pieces together to make the final product. They may need to do finishing work on the product, such as filing and smoothing surfaces. Depending on the size and complexity of the device, the production process may take weeks or months to complete.

Modern technology is changing the way tools are developed and produced. Firms now commonly use computer-aided design to develop products and parts, and to design the tooling to make the parts. These tool drawings are then processed by a computer program to calculate cutting paths and the sequence of operations. Once these instructions are developed, computer numerical control tool machines are usually used to produce the individual components of the tool. Often, these programs are stored for future use.