Crane classifications and what they mean to your business

You've probably heard someone (maybe us!) refer to a crane as being a certain class, using letters from A to F. That's thanks to the Crane Manufacturers Association of America, who recognized it was important to give material handlers a standardized, objective way to tell whether a crane used in a particular application should perform well and safely. This article explains each of the six classes to help you determine what class of crane is recommended for your situation.

The first thing to know is the criteria used to evaluate a crane so that it can be assigned a particular class. There are six criteria: service (how often the crane will be used), speed (how quickly the crane can move material or equipment, measured in lifts per hour), maintenance requirements (how often the crane needs to be serviced), distance (how high the crane needs to move the lifted materials), rated capacity (the average rated load of material that must be moved), and service conditions (the environment the crane will operate in and how easy it is to service it).

Standby or infrequent service


The lightest duty crane classification. It covers cranes that will be handled with precision, at slow speeds and with long periods between lifts. Capacity loads will be handled when the crane is installed and during occasional maintenance.


Used in: Public utilities, motor rooms, transformer stations.

Light service


Covers cranes that can handle no load to full-rated loads at 2 to 5 lifts per hour, averaging 10 feet per lift.


Used in: Light assembly operations, repair shops, service buildings, warehouses.

Moderate service


These cranes can make 5 to 10 lifts per hour, as long as half of the lifts are below rated capacity. Loads should average 50 per cent of the rated capacity of the crane. The average lift height shouldn’t exceed 15 feet.


Used in: Manufacturing, machine shops, papermill machine rooms.

Heavy service


These cranes can handle 10 to 20 lifts per hour averaging 15 feet of height per lift. Loads at 50 per cent of the crane’s rated capacity can be handled constantly during the work day, with no more than 65 per cent of the lifts at rated capacity.


Used in: Heavy machine shops, steel warehouses, lumber mills, foundries, fabricating plants and container yards.

Severe service


This class of crane can handle loads approaching rated capacity throughout its life, without any height restriction or limits to workload per hour. A crane in this class will be lifting loads near or at its rated capacity an average of 20 times per hour with the highest reliability possible.


Used in: Scrapyards, production mills, cement mills, lumber mills, fertilizer plants, container handling

Continuous severe service


These rare beasts must be able to lift loads approaching rated capacity continuously, with no deterioration over time and without any height restriction or limits to workload per hour. A crane in this class will be lifting loads near or at its rated capacity an average of 20 times per hour. They must provide the highest reliability in harsh environments where access for servicing and maintenance may be limited. Class F cranes are often custom designed for a specific function to ensure ultimate performance and reliability with high capacity loads and constant frequency.


Used in: Specialty industrial settings.

In closing, if you know how much weight your system will need to lift (both its maximum and average load), how high the material will be lifted on average and how many times an hour the material will be lifted, we can help you select the safest and most economical crane for your application and you can avoid pushing it beyond its service rating once it’s installed.