The ASME Hoist Duty Classification is a rating system to make sure a hoist is suitable for the application. It is based on a combination of how often the hoist is used and how much of its capacity is used.
|ASME Duty Classes||Service Classification||Description|
|H1||Infrequent or Standby||Idle 1-6 months, used for installation and/or maintenance|
|H2||Light||Light maintenance, fabrication; capacity loads infrequently handled; randomly distributed loads; low running time|
|H3||Standard||General machining; randomly distributed loads; total running time ≤ 25% of working period|
|H4||Heavy||High volume handling of heavy loads near rated capacity; steel warehousing, machining, foundries; total running time ≤ 50% of working period|
|H5||Severe||bulk material handling with attachments; approach continuous operation|