ASME Classifications

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