What Machinists and Tool and Die Makers Do

Machinists and tools and die makers set up and operate a variety of computer-controlled or mechanically-controlled machine tools to produce precision metal parts, instruments, and tools.

Duties

Machinists typically do the following:

• Work from blueprints, sketches, or computer-aided design (CAD) or computer-aided manufacturing (CAM) files
• Set up, operate, and tear down manual, automatic, or computer numeric controlled (CNC) machine tools
• Calculate dimensions using measuring instruments
• Install, align, secure, and adjust cutting tools and workpieces
• Monitor the feed and speed of machines
• Turn, mill, drill, shape, and grind machine parts to specifications
• Measure, examine, and test completed products for defects
• Deburr all surfaces of parts or products to ensure that they conform to specifications

Tool and die makers typically do the following:

• Study blueprints, sketches, specifications, or CAD or CAM files for making tools and dies
• Compute and verify dimensions, sizes, shapes, and tolerances of workpieces
• Set up, operate, and tear down conventional, manual, or computer numeric controlled (CNC) machine tools
• File, grind, and adjust parts so that they fit together properly
• Test completed tools or dies to ensure that they meet specifications
• Inspect for proper dimensions and defects
• Smooth and polish surfaces of tools and dies

Machinists use machine tools that are either conventionally controlled or computer numerically controlled, such as lathes, milling machines, and grinders, to produce precision metal parts. Although they may produce large quantities of one part, precision machinists often produce small batches or one-of-a-kind items. The parts that machinists make range from simple bolts of steel or brass to titanium bone screws for orthopedic implants. Hydraulic parts, anti-lock brakes and automobile pistons are other widely known products that machinists make.

Machinists may further be classified by specialty:

• Production machinists produce large quantities of one part, especially parts requiring the use of complex operations and great precision. Many modern machine tools are computer numerically controlled (CNC). CNC machines control the cutting tool speed and do all necessary cuts to create a part. The machinist determines the cutting path, the speed of the cut, and the feed rate by programming instructions into the CNC machine. Many machinists must be able to use both manual and computer-controlled machinery in their job.
• Maintenance machinists repair or make new parts for existing machinery. After an industrial machinery mechanic discovers the broken part of a machine, the machinist gets the broken part. For more information, see the profile on industrial machinery mechanics and maintenance workers. To replace or remanufacture broken parts, maintenance machinists refer to blueprints and do the same machining operations that were needed to create the original part.

Although production machinists are concentrated in a few industries, maintenance machinists work in many manufacturing industries.

Because the technology of machining is changing rapidly, machinists must learn to operate a wide range of machines. Some newer manufacturing processes use lasers, water jets, electrical discharge machines (EDM), or electrified wires to cut the workpiece. Although some of the computer controls are similar to those of other machine tools, machinists must understand the unique capabilities of these different machines. As engineers create new types of machine tools, machinists must constantly learn new machining properties and techniques.

Toolmakers craft precision tools and toolholders that are used to cut, shape, and form metal and other materials. They also produce jigs and fixtures—devices that hold metal while it is bored, stamped, or drilled—and gauges and other measuring devices.

Die makers construct metal forms, called dies, that are used to shape metal in stamping and forging operations. They also make metal molds for diecasting and for molding plastics, ceramics, and composite materials.

Many tool and die makers use computer-aided design (CAD) to develop products and parts. Specifications entered into computer programs can be used to electronically develop blueprints for the required tools and dies. Computer numeric control programmers use CAD and computer-aided manufacturing (CAM) programs to convert electronic drawings into CAM-based computer programs that contain instructions for a sequence of cutting tool operations. Once these programs are developed, CNC machines follow the set of instructions contained in the program to produce the part. Machinists normally operate CNC machines, but tool and die makers are often trained to both operate CNC machines and write CNC programs, and they may do either task.

Source: Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2012-13 Edition