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CMAA Crane Classifications

Annual crane inspections are required by the Crane Manufacturers Association of America (CMAA) based on the number of “starts/hour” and the average percentage of “Full Capacity” being lifted.
At MMI Tank and Industrial Services, we not only build cranes but we can also perform the annual CMAA Crane Certifications for your crane(s).

  • Class A = standby or infrequent service
  • Class B = light service
  • Class C = moderate service
  • Class D = heavy service
  • Class E = severe service
  • Class F = continuous severe service

Class A Crane Classification= standby or infrequent service

Cranes that are infrequently used, service or standby cranes, are labeled “Class A”. These systems are intended to be used at low speed with long periods of idleness between lifts. Cranes that fit this classification include installation, maintenance, and public utility cranes, also transformer stations and motor rooms.

Class B Crane Classification= light service

Cranes designed for light service at low power, or slow speed, are considered “Class B” cranes. These cranes tend to be used in duty cycles with no loads to light loads, with the occasional full load. Typically, Class B Cranes have an average lift range of 10 feet with 2-5 lifts/hr. These cranes are often found in repair shops, assembly facilities, warehouses, and service buildings.

Class C Crane Classifications= moderate service

“Class C” cranes are designed for moderate services. These cranes tend to lift loads that are 50% of their actual lift capacity. Class C cranes have an average lift height of 15 feet and are commonly used in paper mill machine rooms, manufacturing and machine shops.

Class D Crane Classifications= heavy service

Cranes classified as “Class D” like “Class C”, usually carry 50% of their rated capacity, but “D” cranes are constantly in use. These cranes will move 10-20 loads per hour, every workday with an average height of 15 feet and move their loads quickly. You’ll find “Class D” cranes moving heavy equipment in heavy machine shops, fabrication plants, foundries, container yards, steel warehouses, and lumber mills.

Class E Crane Classifications= severe service

“Class E” cranes are made to handle loads that approach their rated capacity, on a regular basis and lift their actual capacity, on average, 20 times/hour. There is no “usual lift height” for “Class E” cranes, they can and do lift a variety of heights. You’ll find these hard-working cranes in lumber mills, cement mills, fertilizer plants. and container yards. “Class E” cranes may require more frequent maintenance.

Class F Crane Classifications = continuous severe service

“F Class” cranes are the biggest and strongest cranes out there! Much like “Class E” cranes, they are used in severe conditions, but on an almost non-stop basis. They’re also expected to lift at their capacity on a nearly non-stop basis, throughout their lifespan. “Class F” are often customized to fit their particular utility and environment, usually industrial settings.

Whatever type of crane you have or need, MMI Tank and Industrial Services can handle your CMAA crane classifications. We can also help you design, build, assemble, retrofit or move your crane as needed. Give us a call for your quote.

Neil Rheinhardt

Millwright/Industrial Division Manager

Questions & Quotes

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