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Machinists use machine tools such as lathes, drill presses, and milling machines to produce precision metal parts. Although they may produce large quantities of one part, machinists usually produce small batches or one-of-a-kind items. They use their knowledge of the working properties of metalssuch as steel, cast iron, aluminum, and brassand their skill with machine tools to plan and carry out the operations needed to make machined products that meet precise specifications.
Machinists first review blueprints or written specifications for a job. Next, they calculate where to cut or bore into the workpiece, how fast to feed the metal into the machine, and how much metal to remove. They then select tools and materials for the job, plan the sequence of cutting and finishing operations, and mark the metal stock to show where these cuts should be made.
After this layout work is completed, machinists perform the necessary machining operations. They position the metal stock on the machine tooldrill presses, lathes, milling machines, or othersset the controls, and make the cuts. Today, new machinery allows various functions to be performed with one setup, which reduces the need for additional, labor-intensive setups, saving time and money. During the machining process, they must constantly monitor the feed and speed of the machine. Machinists must also ensure that the workpiece is being properly lubricated and cooled because the machining of metal products generates a significant amount of heat.
Some machinists, often called production machinists, may produce large quantities of one part, especially parts requiring complex operations and great precision. For unusually sophisticated procedures, expensive machinery is used. Usually, however, large numbers of parts requiring more routine operations are produced by metalworking machine operators (see the statement on metalworking and plastics-working machine operators elsewhere in the Handbook). Other machinists do maintenance workrepairing or making new parts for existing machinery. For example, to repair a broken part, maintenance machinists may refer to blueprints and perform the same machining operations that were needed to create the original part.
Increasingly, the machine tools used to produce metal parts are numerically controlled (NC)that is, they contain an electronic controller that directs the machine's operations. Most NC machines today are computer numerically controlled (CNC), which means that the controllers are computers. The controller "reads" a programa coded list of the steps necessary to perform a specific machining joband runs the machine tool's mechanisms through the steps.
The introduction of computer numerically controlled machines has greatly changed the nature of the work and productivity of machinists. These machines enable machinists to be more productive and to produce parts with a level of precision that is not possible with traditional machining techniques. Furthermore, because precise movements are recorded in the program, they allow this high level of precision to be consistently repeated.
The quality of the products these machines produce depends largely on the programs, which may be produced by machinists or by tool programmersworkers who specialize in programming machine tools.
Tool programmers begin as machinists doby analyzing blueprints, computing the size and position of the cuts, determining the sequence of machine operations, selecting tools, and calculating the machine speed and feed rates. They then write the program in the language of the machine's controller and store it. Skilled machinists may also do programming. In fact, as computer software becomes more user friendly and CNC machines are used more widely, machinists are expected to perform this function more and more.
Machinists may work alone or with tool programmers to check new programs to ensure that machinery will function properly and the output will meet specifications. Because a problem with the program could damage the costly machinery and cutting tools, computer simulations may be used instead of a trial run to check the program. If errors are found, the program must be changed and retested until the problem is resolved. Some programs are modified for use on other jobs with similar specifications, thereby reducing the time and effort needed to start production of a part. A growing number of firms employ computer-aided design (CAD) systems to assist in writing programs.
Most machine shops are well lighted and ventilated. Nevertheless, working around high-speed machine tools presents certain dangers, and workers must follow safety precautions. Machinists must wear protective equipment such as safety glasses to shield against bits of flying metal and earplugs to protect against machinery noise. They must also exercise caution when handling hazardous coolants and lubricants. The job requires stamina because machinists stand most of the day and may lift moderately heavy workpieces.
Some tool programmers work in offices that are near, but separate from, the shop floor. These work areas are usually clean, well lighted, and free of machine noise.
Most machinists and tool programmers work a 40-hour week. Evening and weekend shifts are becoming more common as companies invest in more expensive machinery. Overtime is common during peak production periods.
Machinists and tool programmers held about 376,000 jobs in 1994. Most machinists worked in small machining shops or in manufacturing firms that produce durable goods such as metalworking and industrial machinery, aircraft, or motor vehicles. Maintenance machinists work in most industries that use production machinery. Although machinists and tool programmers work in all parts of the country, jobs are most plentiful in areas where manufacturing is concentrated.
A high school or vocational school education, including mathematics, blueprint reading, metalworking, and drafting, is desirable for becoming a machinist or tool programmer. A basic knowledge of computers and electronics is helpful because of the increased use of computer-controlled machine tools. Experience with machine tools also is helpful. In fact, many of the people who enter these occupations have previously worked as machine tool operators or setters.
Machinist training varies from formal apprenticeship and postsecondary programs to informal on-the-job training. Apprentice programs consist of shop training and related classroom instruction. In shop training, apprentices learn filing, handtapping, and dowel fitting, as well as the operation of various machine tools. Classroom instruction includes math, physics, blueprint reading, mechanical drawing, and shop practices. In addition, as machine shops have increased their use of computer-controlled equipment, training in the operation and programming of numerically controlled machine tools has become essential. A growing number of machinists and tool programmers receive most of their formal training from community colleges.
Qualifications for tool programmers vary widely depending upon the complexity of the job. Basic requirements parallel those of machinists. Employers often prefer skilled machinists, tool and die makers, or those with technical school training. For some specialized types of programming, such as with complex parts for the aerospace or shipbuilding industries, employers may prefer individuals with a degree in engineering.
For those entering tool programming directly, a basic knowledge of computers and electronics is necessary and experience with machine tools is extremely helpful. Classroom training includes an introduction to numerical control and the basics of programming and then advances to more complex topics such as computer-aided design. Trainees start writing simple programs under the direction of an experienced programmer. Although machinery manufacturers are trying to standardize programming languages, currently there are numerous languages in use. Because of this, tool programmers must be able to learn and adapt to new programming languages.
Established workers may also take courses to update their skills and to learn the latest technology and equipment. Some employers offer tuition reimbursement for job-related courses. In addition, when new machinery is introduced, workers receive training in its operationusually from a representative of the equipment manufacturer.
Persons interested in becoming a machinist or tool programmer should be mechanically inclined. They also should be able to work independently and do highly accurate work that requires concentration as well as physical effort.
Workers may advance in several ways. Experienced machinists may become tool programmers; some move into supervisory or administrative positions in their firms; and a few may open their own shops.
Employment of machinists and tool programmers is expected to decline slightly through the year 2005. Nevertheless, job opportunities will be good, as employers continue to report difficulties in attracting workers to machining and tool programming occupations. Therefore, candidates with the necessary mechanical and mathematical aptitudes should encounter ample demand for their skills. Many job openings also will arise each year from the need to replace experienced machinists and programmers who transfer to other occupations or retire.
The number of openings for machinists is expected to be far greater than the number of openings for tool programmers, primarily because the occupation is larger.
Automation is the major factor in the employment decline projected for machinists and tool programmers. The use of computer-controlled machine tools, for example, reduces the time required for machining operations and increases worker productivity. This allows fewer machinists to accomplish the same amount of work previously performed by more workers. Advanced machine tool technology is allowing some programming to be performed on the shop floor by machinists, tool and die makers, and machine operators. These simplified controls are one of the main factors behind the slight employment decline expected for tool programmers in the coming years.
Employment levels in these occupations is influenced by economic cycles; as the demand for machined goods falls, machinists and tool programmers involved in production may be laid off or be forced to work fewer hours. Employment of machinists involved in plant maintenance, however, is often more stable because proper maintenance and repair of costly equipment remain vital concerns even when production levels fall.
Earnings of machinists compare favorably with those of other skilled workers. In 1994, median weekly earnings for machinists were about $520. Most earned between $400 and $690. The lowest paid ten percent of all machinists had median weekly earnings of less than $300; the 10 percent with the highest earnings made more than $880 a week. In addition to their hourly wage, most workers receive typical benefits such as health and life insurance, a pension plan, paid vacations, and sick leave.
Occupations most closely related to that of machinist and tool programmer are the other machining occupations. These include tool and die maker, tool and die designer, tool planner, and instrument maker. Workers in other occupations that require precision and skill in working with metal include blacksmiths, gunsmiths, locksmiths, metal patternmakers, and welders.
Tool programmers apply their knowledge of machining operations, metals, blueprints, and machine programming to write programs that run machine tools. Computer programmers also write detailed instructions for a machinein this case a computer.
For general information about this occupation, contact:
The Association for Manufacturing Technology, 7901 Westpark Dr., McLean, VA 22102.
The National Tooling and Machining Association, 9300 Livingston Rd., Fort Washington, MD 20744.
The Tooling and Manufacturing Association, ATTN: Education Department, 1177 South Dee Rd., Park Ridge, IL 60068.
Precision Metalforming Association, 27027 Chardon Rd., Richmond Heights, OH 44143.
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