Most engineering related materials can be found in the T call number range, although additional resources can be found some other areas too.
QA 76-76.66 Computer programming
QA 100-200 Mathematics
QC 1-999 Physics
T - Technology
T 59.5 - Automation
TA 1-800 Fiber optics
TA 166-167 - Human Engineering (Ergonomics/Human Factors)
TA 401-492 - Materials
TJ - Robots
TJ 223 Programmable controllers
TK 1-9971 Electrical engineering. Electronics. Nuclear engineering
TK 1-1841 Production of electric energy, powerplants
TK 2000-2891 Dynamoelectric machinery - includes generators, motors, transformers
TK 3001-3521 Distribution or transmission of electric power, electric power circuits
TK 4125-4399 Electric lighting
TK 5101-6720 Telecommunications
TK 7800-8360 Electronics
TK 7885-7895 Computer Engineering/Computer Hardware
TK 9001-9401 Nuclear engineering, Atomic power
TL 1-4050 - Motor Vehicles/Aeronautics/Astronautics