Machinists and tool and die makers set up and operate a variety of computer-controlled and mechanically controlled machine tools to produce precision metal parts, instruments, and tools.
Machinists typically do the following:
Work from blueprints, sketches, or computer-aided design (CAD) and computer-aided manufacturing (CAM) files
Set up, operate, and disassemble manual, automatic, and computer-numeric-controlled (CNC) machine tools
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
Smooth the surfaces of parts or products
Present finished workpieces to customers and make modifications if needed
Tool and die makers typically do the following:
Read blueprints, sketches, specifications, or CAD and CAM files for making tools and dies
Compute and verify dimensions, sizes, shapes, and tolerances of workpieces
Set up, operate, and disassemble conventional, manual, and CNC machine tools
File, grind, and adjust parts so that they fit together properly
Test completed tools and dies to ensure that they meet specifications
Smooth and polish the surfaces of tools and dies
Machinists use machine tools, such as lathes, milling machines, and grinders, to produce precision metal parts. Many machinists must be able to use both manual and CNC machinery. 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.
Although workers 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 steel bolts to titanium bone screws for orthopedic implants. Hydraulic parts, antilock brakes, and automobile pistons are other widely known products that machinists make.
Some machinists repair or make new parts for existing machinery. After an industrial machinery mechanic discovers a broken part in a machine, a machinist remanufactures the part. The machinist refers to blueprints and performs the same machining operations that were used to create the original part in order to create the replacement.
Because the technology of machining is changing rapidly, workers must learn to operate a wide range of machines. Some newer manufacturing processes use lasers, water jets, and 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 and features of different machines. As engineers create new types of machine tools, machinists must learn new machining properties and techniques.
Toolmakers craft precision tools 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 die casting and for molding plastics, ceramics, and composite materials.
Many tool and die makers use CAD to develop products and parts. Designs are entered into computer programs that produce blueprints for the required tools and dies. Computer-numeric control programmers, found in the metal and plastic machine workers profile, convert CAD designs into CAM 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 often are trained to both operate CNC machines and write CNC programs and thus may do either task.