Optical, acoustical, and laser measuring devices commonly ensure that work meets specifications. Although machinists and tool programmers perform many similar duties, jobs can vary greatly. Some machinists, often called production machinists, may produce large quantities of one part, especially parts needing unusually complex operations, great precision, or when unusually sophisticated, expensive machinery is used. Other machinists do maintenance work repairing 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.
Machinists frequently use lathes to make round or circular parts.
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 cleaning and disposing of coolants and lubricants because many of these materials can be hazardous. The job requires stamina because machinists stand most of the day and may lift moderately heavy workpieces.