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408
Metalworking and Plastics-Working Machine Operators

(A list of D.O.T.  codes is available on request.  See page 468.)

Nature of the Work

Consider the parts of a toaster the metal or plastic housing or the
lever that lowers the toast, for example.  These parts, and many
other metal and plastic products, are produced by metal and
plastics-working machine operators.  In fact, manual and numerical
control machine tool operators in the metalworking and plastics
industries play a major part in producing most of the consumer
products on which we rely daily.

   These workers can be separated into two groups: Those who set up
machines for operation and those who tend the machines during
production.  Setup workers prepare the machines prior to production
and may adjust the machinery during operation.  Operators and
tenders, on the other hand, primarily monitor the machinery during
operation, sometimes loading or unloading the machine or making
minor adjustments to the controls.  Many workers do both set up and
operate the equipment.  Because the set-up process requires an
understanding of the entire production process, setters usually have
more training and are more highly skilled than those who simply
operate or tend the machinery.

   Setters, operators, tenders, and set-up operators are usually
identified by the type of machine with which they work.  Some
examples of specific titles are screw machine operator,
plastics-molding machine setup operator, and lathe tender.  Although
some workers specialize in one or two types of machinery, many are
trained to set up or operate a variety of machines.  Job duties
usually vary based on the size of the firm as well as on the type of
machine being operated.

   Metalworking machine setters and operators set up and tend machines
that cut and form all types of metal parts.  Traditionally, setup
workers plan and set up the sequence of operations according to
blueprints, layouts, or other instructions.  They adjust speed,
feed, and other controls, choose the proper coolants and lubricants,
and select the instruments or tools for each operation.  Using
micrometers, gauges, and other precision measuring instruments, they
may compare the completed work with the tolerance limits stated in
the specifications.

   Although there are many different types of metalworking machine
tools that require specific knowledge and skills, most operators
perform similar tasks.  Whether tending grinding machines that
remove excess material from the surface of machined products or
presses that extrude metal through a die to form wire, operators
usually perform simple, repetitive operations that can be learned
quickly.  Typically, these workers place metal stock in a machine on
which the operating specifications have already been set.  They may
watch one or more machines and make minor adjustments according to
their instructions.  Regardless of the type of machine they operate,
machine tenders usually depend on skilled setup workers for major
adjustments when the machines are not functioning properly.

   Plastics working machine operators set up and tend machines that
transform plastic compounds chemical based products that can be
produced in powder, pellet, or syrup form into a wide variety of
consumer goods such as toys, tubing, and auto parts.  These products
are produced by various methods, of which injection molding is the
most common.  The injection molding machine heats a plastic compound
and forces it into a mold.  After the part has cooled and hardened,
the mold opens and the part is released.  Many common kitchen
products are produced using this method.  To produce long parts such
as pipes or window frames, on the other hand, an extruding machine
is usually employed.  These machines force a plastic compound
through a die that contains an opening of the desired shape of the
final product.  Yet another type of plastics working technique is
blow molding.  Blow-molding machines force hot air into a mold which
contains a plastic tube.  As the air moves into the mold, the
plastic tube is inflated to the shape of the mold and a plastic
container is formed.  The familiar 2-liter soft drink bottles are
produced using this method.

   Regardless of the process used, plastics-working machine operators
check the materials feed, the temperature and pressure of the
machine, and the rate at which the product hardens.  Depending on
the type of equipment in use, they may also load material into the
machine, make minor adjustments to the machinery, or unload and
inspect the finished products.  Plastics-working machine operators
also remove clogged material from molds or dies.  Because molds and
dies are quite costly, operators must exercise proper care to avoid
damaging them.

   Metal and plastics-working machine operators are increasingly being
called upon to work with numerically controlled (NC) equipment.
These machine tools have two major components: An electronic
controller and a machine tool.  Almost all NC machines today are
computer numerically controlled (CNC), which means that the
controllers are computers.  The controller directs the mechanisms of
the machine tool through the positioning and machining described in
the program or instructions for the job.  A program could contain,
for example, commands that cause the controller to move a drill bit
to certain spots on a workpiece and drill a hole at each spot.

   Each type of CNC machine tool, such as a milling machine, a lathe,
or a punch press, performs a specific task.  A part may be worked on
by several machines before it is finished.  CNC machines are often
used in computer-integrated manufacturing (CIM) systems.  In these
systems, automated material handling equipment moves workpieces
through a series of work stations where machining processes are
computer numerically controlled.  In some cases, the workpiece is
stationary and the tools change automatically.  Although the
machining is done automatically, numerically controlled machine
tools must be set up and used properly in order to obtain the
maximum benefit from their use.  These tasks are the responsibility
of numerical-control machine-tool operators or, in some instances,
machinists.  (See the statement on machinists and tool programmers
elsewhere in the Handbook.)

   Like the duties of manual metal and plastics machine operators, the
duties of numerical-control machine-tool operators vary.  In some
shops, operators tend just one machine.  More likely, however, they
might tend a number of machines or do some programming.  As a
result, the skill requirements of these workers vary from job to
job.  Although there are many variations in operators' duties, they
generally involve many of the tasks described below.

   Working from given instructions, operators load programs that are
usually stored on floppy disks into the controller.  They also
securely position the workpiece, attach the necessary tools, and
check the coolants and lubricants.  Many numerically controlled
machines are equipped with automatic tool changers, so operators may
also load several tools in the proper sequence.  In addition, heat
generated by machining could damage the cutting tools and the part
being machined, so operators must ensure that the proper coolants
and lubricants are being used.  This entire process may require a
few minutes or several hours, depending on the size of the workpiece
and the complexity of the job.

   A new program must be debugged, or adjusted, to obtain the desired
results.  If the tool moves to the wrong position or makes a cut
that is too deep, for example, the program must be changed so that
the job is done properly.  Sometimes an NC operator will debug
programs, but more often a machinist or tool programmer will perform
this function.  (See the statement on machinists and tool
programmers elsewhere in the Handbook.) A new generation of machine
tool technology called direct numerical control allows operators to
make changes to the program and enter new specifications via
menu-driven mini computers on the shop floor.

   Because numerically controlled machine tools are very expensive, an
important duty of operators is to monitor the machinery to prevent
situations that could result in costly damage to the cutting tools
or other parts.  The extent to which the operator performs this
function depends on the type of job as well as the type of equipment
being used.  Some numerically controlled machine tools automatically
monitor and adjust machining operations.  When the job has been
properly set up and the program has been checked, the operator may
only need to monitor the machine as it operates.  These operators
often set up and monitor more than one machine.  Other jobs require
frequent loading and unloading, tool changing, or programming.
Operators may check the finished part using micrometers, gauges, or
other precision inspection equipment to ensure that it meets
specifications.  Increasingly, however, this function is being
performed by numerically controlled machine tools that are able to
inspect products as they are being produced.

   CNC machines are changing the nature of the work that machine
setters and operators perform.  For example, computer-controlled
machines simplify setups by using formerly tested computer programs
for new workpieces.  If a workpiece is similar to one previously
produced, small adjustments can be made to the old program instead
of developing a new program from scratch.  Also, operators of this
equipment have less physical interaction with the machinery or
materials.  They primarily act as troubleshooters, monitoring
machines on which the loading, forming, and unloading processes are
often controlled by computers.

   Automated machinery has increased the productivity of many machine
operators.

Working Conditions

Most metalworking and plastics-working machine operators work in
areas that are clean, well lit, and well ventilated.  Regardless of
setting, all of these workers operate powerful, high-speed machines
that can be dangerous if strict safety rules are not observed.  Most
operators wear protective equipment such as safety glasses and
earplugs to protect against flying particles of metal or plastic and
noise from the machines.  Other required equipment varies by work
setting and by machine.  For example, workers in the plastics
industry who work near materials that emit dangerous fumes or dust
must wear face masks or self-contained breathing apparatuses.

   Most metal and plastics working machine operators work a 40-hour
week, but overtime is common during periods of increased production.
The industries in which metal and plastics workers are concentrated
average 3 or 4 hours of overtime per week.  Because many
metalworking and plastics working shops operate more than one shift
daily, some operators work nights and weekends.

   The work requires stamina because operators are on their feet much
of the day and may do moderately heavy lifting.  Approximately 35-40
percent of these workers are union members; the metalworking
industries have a higher rate of unionization than the plastics
industry.

Employment

Metalworking and plastics-working machine operators held about
1,378,000 jobs in 1992.  Of these, 1,305,000 were manual machine
operators, and 73,000 were NC machine operators.  Eight out of every
10 of these workers are found in five industries: Fabricated metal
products, industrial machinery and equipment, miscellaneous plastic
products, transportation equipment, and primary metals.  Table 1
shows the distribution of employment of metal and plastics-working
machine operators by detailed occupation.


Table 1.  Distribution of Metal and plastics-working machine
operators by detailed occupation, 1992

Occupation Percent

Machine tool cutting and forming machine setters and operators....49
Molding machine setters and operators.............................14
Sheetmetal workers and duct installers...........................  8
Combination machine tool setters and operators...................  7
Numerical control machine operators..............................  5
Plating machine setters and operators............................  4
Metal fabricators, structural metal products.....................  3
Heaters and heat treating machine setters and operators..........  2

SOURCE: Bureau of Labor Statistics

Training, Other Qualifications, and Advancement

Most metal and plastics-working machine operators learn their skills
on the job.  Trainees begin by observing and assisting experienced
workers, often in formal training programs.  Under supervision they
may supply material, start and stop the machine, or remove finished
products from the machine.  As part of their training they advance
to more difficult tasks like adjusting feed speeds, changing cutting
tools, or inspecting a finished product for defects.  Eventually
they become responsibile for their own machine or machines.

   The complexity of equipment largely determines the time required to
become an operator.  Most operators learn the basic machine
operations and functions in a few weeks, but they may need several
years to become a skilled operator or to advance to the more highly
skilled job of setup operator.

   Although setup operators perform many of the same tasks as skilled
machine operators, they also need to have a thorough knowledge of
the machinery and of the products being produced.  Setup operators
often study blueprints, plan the sequence of work, make the first
production run, and determine which adjustments need to be made.
Strong analytical abilities are particularly important to perform
this job.  Some companies have formal training programs for setup
operators that combine classroom instruction with on-the-job
training.

   CNC machine tool operators undergo similar training.  Working under
a supervisor or an experienced operator, trainees learn to set up
and run one or more kinds of numerically controlled machine tools.
Trainees usually learn the basics of their jobs within a few months.
However, the length of the training period varies with the number
and complexity of the machine tools the operator will run and with
the individual's ability.  If the employer expects operators to
write programs, trainees may attend programming courses offered by
machine tool manufacturers or technical schools.  These courses
usually last a couple of weeks.

   Although no special education is required for most operating jobs,
employers prefer to hire applicants with good basic skills.  Many
require employees to have a high school education and to read,
write, and speak English.  This is especially true for numerical
control machine operators, who may need to be retrained often in
order to learn to operate new equipment.  Because machinery is
becoming more complex and shop floor organization is changing,
employers increasingly look for persons with good communication and
interpersonal skills.  Mechanical aptitude, manual dexterity, and
experience working with machinery are also pluses.  Those interested
in becoming a metal or plastics-working machine operator can improve
their employment opportunities by completing high school courses in
shop, mathematics, and blueprint reading and by gaining a working
knowledge of the properties of metals and plastics.

   Advancement for operators usually takes the form of higher pay,
although there are some limited opportunities for operators to
advance to new positions as well.  For example, they can become
multiple machine operators, setup operators, or trainees for the
more highly skilled positions of machinist or tool and die maker.
Manual machine operators can move on to CNC equipment when it is
introduced into their establishments.  Some setup workers and CNC
operators may advance to supervisory positions.  CNC operators who
have substantial training in numerical control programming may
advance to the higher paying job of tool programmer.  (See
statements on machinists and tool programmers, and tool and die
makers found elsewhere in the Handbook.)

Job Outlook

Overall employment of metal and plastics-working machine operators
is expected to decline through the year 2005.  This decline is
likely to affect metalworking machine operators more than those
working with plastics machines.  In addition, setters and more
highly skilled operators are more likely to be retained by firms
than are semi-skilled operators and tenders.  In spite of the
overall employment decline, however, a large number of jobs will
become available each year as current operators and setters transfer
to other occupations or leave the labor force.

   A major factor driving the employment decline is the increasing
productivity resulting from computer-controlled equipment.  In order
to remain competitive, many firms are adopting this technology to
improve quality and lower production costs.  Computer-controlled
equipment allows operators to simultaneously tend a greater number
of machines and often makes setup easier, thereby reducing the
amount of time setup workers spend on each machine.  For these
reasons, employment of CNC machine operators is expected to increase
in the future despite the decline in machine operators as a whole.
Lower-skilled positions like manual machine tool operators and
tenders are more likely to be eliminated by increasing automation
than those of setters and set up operators, whose higher skills are
more in demand and whose job functions are less easily automated.

   The demand for metal and plastics machine operators largely mirrors
the demand for the parts they produce.  In recent years, plastic
products have been substituted for metal goods in many consumer and
manufacturing products.  Although the rate of substitution may slow
in the future, this process is likely to continue and should result
in a relatively stronger demand for machine operators in plastics
than in metalworking.  Both industries, however, face stiff foreign
competition that is limiting the demand for domestically-produced
parts.  One way that larger U.S.  producers have responded to this
competition is by moving production operations to other countries in
order to reduce labor costs.  These moves are likely to continue and
will further reduce employment opportunities for metal and
plastics-working machine tool operators in the United States.

   Workers with a thorough background in machine operations, exposure
to a variety of machines, and a good working knowledge of the
properties of metals and plastics will be best able to adjust to
this changing environment.  In addition, new shopfloor arrangements
will reward workers with good basic mathematics and reading skills,
good communication skills, flexibility, and the ability and
willingness to learn new tasks.  Those interested in working with
CNC machine tools will most likely need to have a high school
education and should be familiar with several types of machines and
operating systems.

Earnings

Median weekly earnings for most metal and plastics-working machine
operators were $413 in 1992.  The middle 50 percent earned between
$300 and $536.  The top 10 percent earned over $697 and the bottom
10 percent earned less than $236.  Plastic molding machine operators
earned somewhat less, about $359 a week.  Numerical-control
machine-tool operators earned between $450 and $500 a week in 1992,
according to the limited data available.

   Earnings of production workers vary considerably by industry,
however.  Average weekly wages for production workers in industries
where employment of metal and plastics-working machine operators is
concentrated are shown in the following tabulation.

Transportation equipment..........................................$633
Primary metals industries......................................... 590
Industrial machinery and equipment................................ 525
Fabricated metal products......................................... 475
Rubber and misc. plastics products................................ 433

   Most machine operators receive standard benefits such as pension
plans, vacation and sick leave, and retirement plans.

Related Occupations

Workers in occupations closely related to metalworking and
plastics-working machine occupations include machinists, tool and
die makers, extruding and forming machine operators producing
synthetic fibers, woodworking machine operators, and metal
patternmakers.  Numerical-control machine-tool operators may program
CNC machines or alter existing programs, which are functions closely
related to those performed by NC machine tool programmers.

Sources of Additional Information

   For general information about the metalworking trades, 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, 1177 South Dee Rd., Park
Ridge, IL 60068.

   The National Screw Machine Products Association, 6700 West Snowville
Rd., Brecksville, OH 44141.

   Information on educational programs in plastics technology and
polymer sciences is available from:

   The Society of the Plastics Industry, Inc., 1275 K St.  NW.,
Washington, DC 20005.

   The Plastics Education Foundation of The Society of Plastics
Engineers, Inc., 14 Fairfield Dr., Brookfield, CT 06804-0403.


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