DECIMAL CLASSIFICATION 
4 ® 
620 Engineering 
See also 690 Bilding; 721 Architectural construction 
JL 
02 
03 
.04 
05 
.06 
.07 
08 
.09 
I 
SUMMARY 
Applied mechanics Engineering materials 
Mechanical engineering 
Steam engineering 
Hydraulic engins or motors 
Electric engineering 
Air and gas engins and other motors 
Pneumniatic machinery Refrigerating machines 
Blowing and pumping engins 
Mills Factories Engineering works 
Millwork Hoisting and conveying machinery 
Machine tools 
Mining engineering 
Military and naval engineering 
Naval architecture 
Bridges and roofs 
Railroad and road engineering 
Canal engineering 
River, harbor and general hydraulic engineering 
Sanitary engineering 
Other engineering industries 
620.1 
921 
622 
6213 
6 
& 
624 
625 
626 
627 
628 
520 
Statistics 
Duantities and cost 
Contracts and specifications 
Designs and drawings 
Executiv 
Working and maintenance 
Laws and regulations 
Patents 
Reports 
Applied mechanics Engineering materials 
Class here general works on materials with reference to their fitness in engineer 
ing See also 691 Bilding materials 
Strength of materials General theory 
General works considering various materials. Tor particular 1aaterials see 
620.12—.19 Provision is made below for classing tests on 2 different bases: 
1) by character of test, 2) by material tested. Class under material rather 
than under test when the two conflict. See also note under 620.112 
For theory or mechanics of structures see 624: for theories of construction of 
bildings see 690.1 
General 
This hed is left for specialists wishing to analyze general works or collect 
clippings and notes too limited for .11 yet not specific enough to be put 
with a particular test or material. Libraries are unlikely to need any 
general hed except 620.17