Mechanical engineering in general. Nuclear technology. Electrical engineering. Machinery - 621
Subsections for UDC 621
(Mechanical engineering in general. Nuclear technology. Electrical engineering. Machinery)- Pneumatic energy, machinery and tools. Refrigeration
- Fluids handling, storage and distribution plant and techniques
- Machine elements. Motive power engineering. Materials handling. Fixings. Lubrication
- Working or machining with chip formation. Abrasive working. Hammers and presses
- Heat engines (except steam engines)
- Mechanical technology in general: processes, tools, machines, equipment
- Electrical engineering