Production · Holland code RC

Crushing, Grinding, and Polishing Machine Setters, Operators, and Tenders

Set up, operate, or tend machines to crush, grind, or polish materials, such as coal, glass, grain, stone, food, or rubber.

Also called: Grinder, Machine Operator, Miller, Preparation Operator (Prep Operator), Beveler Operator, Cullet Trucker, Grinder Operator, Machine Tender.

O*NET 51-9021.00

At a glance

US median annual pay: $48,540; Middle half earn $40,430 to $60,040. BLS OEWS, May 2025.
Most common education: High School Diploma or the equivalent (such as a GED); 62% of workers surveyed by O*NET report this level.
Preparation needed: Job Zone 2 of 5; Some preparation. Zone 1 is little or none; zone 5 is graduate-level.

What the work involves

The tasks workers in this occupation rate as most important, from the O*NET survey.

Observe operation of equipment to ensure continuity of flow, safety, and efficient operation, and to detect malfunctions.
Clean, adjust, and maintain equipment, using hand tools.
Tend accessory equipment, such as pumps and conveyors, to move materials or ingredients through production processes.
Move controls to start, stop, or adjust machinery and equipment that crushes, grinds, polishes, or blends materials.
Notify supervisors of needed repairs.
Weigh or measure materials, ingredients, or products at specified intervals to ensure conformance to requirements.
Test samples of materials or products to ensure compliance with specifications, using test equipment.
Mark bins as to types of mixtures stored.

Skills and knowledge it leans on

Skills

Monitoring3.1 / 5
Reading Comprehension3.0 / 5
Active Listening3.0 / 5
Speaking3.0 / 5
Writing2.9 / 5
Critical Thinking2.9 / 5

Knowledge areas

Administration and Management3.5 / 5
Production and Processing3.4 / 5
English Language3.2 / 5
Education and Training3.2 / 5
Public Safety and Security3.0 / 5
Mathematics3.0 / 5

Importance ratings on O*NET’s 1 to 5 scale. Higher means the occupation depends on it more.

Who tends to enjoy it

How strongly this occupation draws on each of the six Holland interest types, which is the same profile the career interests test compares you against.

Realistic97
Investigative19
Artistic0
Social0
Enterprising7
Conventional60

The same work abroad

Other countries classify jobs differently, so these are the closest matches through the international ISCO-08 standard, not exact equivalents.

European occupation titles (ESCO)

grinding machine operator · DE CNC-Schleifer/CNC-Schleiferin · FR rectifieur/rectifieuse
mineral crushing operator · DE Brechermaschinist/Brechermaschinistin · FR opérateur de broyeur/opératrice de broyeur
mineral processing operator · DE Mineralaufbereiter/Mineralaufbereiterin · FR opérateur de machines de traitement du minerai/opératrice de machines de traitement du minerai
stone polisher · DE Steinschleifer/Steinschleiferin · FR polisseur de pierre/polisseuse de pierre
surface grinding machine operator · DE Flachschleifer/Flachschleiferin · FR opérateur de rectifieuse de surfaces planes/opératrice de rectifieuse de surfaces planes
cylindrical grinder operator · DE Rundschleifer/Rundschleiferin · FR opérateur de rectifieuse cylindrique/opératrice de rectifieuse cylindrique

Closest UK occupation groups (SOC 2020)

Metal machining setters and setter-operators (5221)40,400 employed
Food, drink and tobacco process operatives (8111)129,900 employed
Metal working machine operatives (8120)28,100 employed

Employment is the UK Annual Population Survey for April 2025 to March 2026, all workers in the group, which can be broader than this one occupation.

Pay across Europe, for the whole group

Median annual earnings of all employees in “Plant and machine operators and assemblers”. This is the broad ISCO group this occupation falls in, not the occupation itself, so treat it as context for the wage level, not as a salary for this job.

Median annual earnings, Plant and machine operators and assemblers, by country
Country	Median pay
Belgium	€39,630
Netherlands	€37,567
Austria	€37,304
Sweden	€36,005
Germany	€34,433
Ireland	€32,617
France	€28,550
Italy	€28,330
Spain	€24,409
Portugal	€11,309
Poland	€10,259

Eurostat Structure of Earnings Survey, businesses with ten or more employees outside public administration, in euro and not adjusted for the cost of living. Reference years differ between sources: the US, Japan and Europe figures on this page come from different survey years, so compare them as rough levels, not to the euro or yen.

Exposure to AI

This occupation sits in the lower third of the 774 occupations scored, with an exposure score of -1.04. The scores are standardized across those occupations, so 0 is the average and a score of 1 is about one standard deviation above it.

Our note on reading it: the dataset links AI applications to the abilities that occupations require, so the score reflects overlap between the two. It is a comparison between occupations, not a forecast about jobs. It does not say whether exposure means tasks are replaced or workers get more done with the tools, and it says little about one employer or one role.

Source: Felten, E., Raj, M., & Seamans, R. (2021). Occupational, industry, and geographic exposure to artificial intelligence: A novel dataset and its potential uses. Strategic Management Journal, 42(12), 2195-2217. Matched to this page by 6-digit SOC code (51-9021).

Is it a fit for you?

Interest is one input, alongside ability, pay and what is hiring near you. The career interests test takes about thirteen minutes and ranks occupations by how closely their profile matches yours.

Take the career interests test