Mechanical engineering in general. Nuclear technology. Electrical engineering. Machinery
Scope Note
Class information about particular kinds of machinery at the number for the subject
Broader class
62  Engineering. Technology in general
Narrower classes
621.1Heat engines in general. Generation, distribution and use of steam. Steam engines. Boilers
621.22Hydraulic energy. Water power. Hydraulic machinery
621.3Electrical engineering
621.4Heat engines (except steam engines)
621.5Pneumatic energy, machinery and tools. Refrigeration
621.6Fluids handling, storage and distribution plant and techniques
621.7Mechanical technology in general: processes, tools, machines, equipment
621.8Machine elements. Motive power engineering. Materials handling. Fixings. Lubrication
621.9Working or machining with chip formation. Abrasive working. Hammers and presses