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Sets up and operates conventional, special-purpose, and
numerical control (Nc) machines and machining centers to
fabricate metallic and nonmetallic parts, and fits and assembles
mahcined parts into complete units, applying knowledge of
machine shop theory and procedures, shop mathematics,
machinability of materials, and layout techniques: Studies
blueprints, sketches, drawings, manuals, specifications, or
sample part to determine dimensions and tolerances of finished
workpiece, sequence of operations, and setup requirements.
Measures, marks, and scribes dimensions and reference poitns on
material or workpiece as guides for subsequent machining
[Lay-Out Worker (machine shop) 600.281-018].
Selects, aligns,
and secures holding fixtures, cutting tools, attachments,
accessories, and materials on machines, such as mills, lathes,
jig borers, grinders, and shpaers.
Calculates and sets controls
to regulate machining factors, such as speed, feed, coolant
flow, and depth and angle of cut, or enters commands to
retrieve, input, or edit computerized machine control media.
Starts and observes machine operation to detect malfunctions or
out-of-tolerance machining, and adjusts machine controls or
control media as required.
Verifies conformance of finished
workpiece to specifications, using precision measuring
instruments. Sets up and operates machine on trial run to verify
accuracy of machine settings or prorgammed control data. Fits
and assembles parts into complete assembly, uisng jigs,
fixtures, surface plate, surface table, handtools, and power
tools. Verifies dimensions and aligmnent of assembly, using
measuring instruments, such as micrometers, height gauges, and
gauge blocks.
May install machined replacement parts in
mechanisms, machines, and equipment, and test operatoin of unit
to ensure functionality and performance. May operate welding
equipment to cut or weld prats. May develop specifications from
general description and draw sketch of part or proudct to be
fabricated. May confer with engineers, production personnel,
programmers, or others to resolve machining or assembly
problems. May specialize in setting up and operating Nc machines
and machining centers and be designated Numerical Control
Machine Machinist (machine shop); or set up and operate Nc
machines linked to automated storage, retrieval, and moving
devices and be designated Flexible Machining System Machinist
(machine shop).
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