URI
Notation
621.4
Caption
Heat engines (except steam engines)
Application Note
For details of machinery and processes use special auxiliary numbers 62-1/-9
See also
621.1Heat engines in general. Generation, distribution and use of steam. Steam engines. Boilers
662.6/.9Heat economy. Fuel economy. Fuels. Heating
Broader class
621  Mechanical engineering in general. Nuclear technology. Electrical engineering. Machinery