Library of Congress Classification System
T - Technology
| T | 1-995 | General Technology. |
| 10.5-11.9 | Communication of Technical Information | |
| 11.95-12.5 | Industrial Directories | |
| 14.7-33 | History of Technology | |
| 44-51 | General Works | |
| 55-55.3 | Industrial Satety, Industrial Accident Prevention | |
| 55.4-60.8 | Industrial Engineering, Management Engineering | |
| 57-57.97 | Applied Mathematics, Quantitative Methods | |
| 57.6-57.97 | Operations Research, Systems Analysis | |
| 58.4 | Managerial Control Systems | |
| 58.5-58.64 | Information Technology | |
| 58.6-58.62 | Management Information Systems | |
| 58.7-58.8 | Production Capacity, Manufacturing Capacity | |
| 59-59.2 | Standardization | |
| 59.5 | Automation | |
| 59.7-59.77 | Human Engineering in Industry, Man-Machine Systems | |
| 60-60.8 | Work Measurement, Methods Engineering | |
| 61-173 | Technical Education, Technical Schools | |
| 173.2-174.5 | Technological Change | |
| 175-178 | Industrial Research, Research and Development | |
| 201-342 | Patents, Trademarks | |
| 351-385 | Mechanical Drawing, Engineering Graphics | |
| 391-995 | Exhibitions, Trade Shows, World's Fairs | |
| TA | 1-2040 | General Engineering, General Civil Engineering. |
| 164 | Bioengineering | |
| 165 | Engineering Instruments, Meters, etc., Industrial Instrumentation | |
| 166-167 | Human Engineering | |
| 168 | Systems Engineering | |
| 170-171 | Environmental Engineering | |
| 174 | Engineering Design | |
| 177.4-185 | Engineering Economy | |
| 190-194 | Management of Engineering Works | |
| 197-198 | Engineering Meteorology | |
| 213-215 | Engineering Machinery, Tools, and Implements | |
| 329-348 | Engineering Mathematics, Engineering Analysis | |
| 349-359 | Mechanics of Engineering, Applied Mechanics | |
| 365-367 | Acoustics in Engineering, Acoustical Engineering | |
| 401-492 | Materials of Engineering and Construction, Mechanics of Materials | |
| 495 | Disasters and Engineering | |
| 501-625 | Surveying | |
| 630-695 | Structural Engineering (General) | |
| 703-712 | Engineering Geology. Rock and Soil Mechanics, Underground Construction | |
| 715-787 | Foundations, Earthwork | |
| 800-820 | Tunnels, Tunneling | |
| 1001-1280 | Transportation Engineering (General) | |
| 1501-1820 | Applied Optics, Photonics | |
| 2001-2040 | Plasma Engineering, Applied Plasma Dynamics | |
| TC | 1-1800 | |
| 1-978 | Hydraulic Engineering | |
| 160-181 | Technical Hydraulics | |
| 183-201 | General Preliminary Operations, Dredging, Submarine Building | |
| 203-380 | Harbors and Coast Protective Works, Coastal Engineering, Lighthouses | |
| 401-506 | River, Lake, and Water-Supply Engineering (General) | |
| 530-537 | River Protective Works, Regulation, Flood Control | |
| 540-558 | Dams, Barrages | |
| 601-791 | Canals and Inland Navigation, Waterways | |
| 801-978 | Irrigation Engineering, Reclamation of Wasteland, Drainage | |
| 1501-1800 | Ocean Engineering | |
| TD | 1-1066 | Environmental Technology, Sanitary Engineering. |
| 159-168 | Municipal Engineering | |
| 169-17185 | Environmental Protection | |
| 172-193.5 | Environmental Pollution | |
| 194-195 | Environmental Effects of Industries and Plants | |
| 201-500 | Water Supply for Domestic and Industrial Purposes | |
| 419-428 | Water Pollution | |
| 429.5-480.7 | Water Purification, Water Treatment and Conditioning, Saline Water Conversion | |
| 481-493 | Water Distribution Systems | |
| 511-780 | Sewage Collection and Disposal Systems | |
| 783-812.5 | Municipal Refuse, Solid Wastes | |
| 813-870 | Street Cleaning, Litter and its Removal | |
| 878-894 | Special Types of Environmental Pollution (including soil, air, and noise pollution) | |
| 895-899 | Industrial and Factory Sanitation and Wastes | |
| 920-934 | Rural and Farm Sanitary Engineering | |
| 940-949 | Low Temperature Sanitary Engineering | |
| 1020-1066 | Hazardous Substances and Their Disposal | |
| TE | 1-450 | Highway Engineering. |
| 175-176.5 | Highway Design, Interchanges and Intersections | |
| 177-178.8 | Roadside Development, Landscaping | |
| 200-205 | Materials for Roadmaking | |
| 206-209.5 | Location Engineering | |
| 210-228.3 | Construction Details (including foundations, maintenance, equipment) | |
| 250-278.8 | Pavements and Paved Roads | |
| 279 | Streets | |
| 279.5-298 | Pedestrian Facilities | |
| 280-295 | Sidewalks, Footpaths, Flagging | |
| 298 | Curbs, Curbstones | |
| TF | 1-1620 | Railroads. |
| 200-320 | Railway Construction | |
| 340-499 | Railway Equipment and Supplies | |
| 501-668 | Railway Operation and Management | |
| 670-851 | Local and Light Railways | |
| 840-851 | Elevated Railways and Subways | |
| 855-1127 | Electric Railways | |
| 1300-1620 | High Speed Ground Transportation | |
| TG | 1-470 | Bridge Engineering. |
| 21-127 | Country Divisions | |
| 215-255 | Bridge Legislation and Laws (now Class K) | |
| 327-418 | Special Types of Bridges | |
| 420-470 | Bridges for Special Uses | |
| TH | 1-9745 | Building Construction |
| 845-895 | Architectural Engineering, Structural Engineering of Buildings | |
| 900-915 | Construction Equipment in Buildings | |
| 1000-1725 | Systems of Building Construction. | |
| 2025-3000 | Details in Building Design and Construction (including walls, roofs) | |
| 3301-3411 | Maintenance and Repair | |
| 4021-4977 | Buildings: Construction with Reference to Use (including public buildings, dwellings) | |
| 5011-5701 | Construction by Phase of Work | |
| 6014-6081 | Environmental Engineering of Buildings, Sanitary Engineering of Buildings | |
| 6101-6887 | Plumbing and Pipefitting | |
| 7005-7699 | Heating and Ventilation, Air Conditioning | |
| 7700-7975 | Illumination, Lighting | |
| 8001-8581 | Decoration and Decorative Furnishings | |
| 9025-9745 | Protection of Buildings (including protection from dampness, fire, burglary) | |
| TJ | 1-1570 | Mechanical Engineering. |
| 163.12-163.25 | Power Resources | |
| 163.26-163.5 | Energy Conservation | |
| 170-179 | Mechanics Applied to Machinery, Dynamics | |
| 181-210 | Mechanical Movements | |
| 210.2-211.47 | Mechanical Devices and Figures, Automata, Ingenious Mechanisms, Robots (General) | |
| 212-225 | Control Engineering Systems, Automatic Machinery (General) | |
| 227-240 | Machine Design and Drawing | |
| 241-254.7 | Machine Construction (General) | |
| 255-265 | Heat Engines | |
| 266-267.5 | Turbines, Turbomachines (General) | |
| 268-740 | Steam Engineering | |
| 603-695 | Locomotives | |
| 751-805 | Miscellaneous Motors and Engines (including gas, gasoline, diesel engines) | |
| 807-830 | Renewable Energy Sources | |
| 836-927 | Hydraulic Machinery | |
| 940-940.5 | Vacuum Technology | |
| 950-1030 | Pneumatic Machinery | |
| 1040-1119 | Machinery Exclusive of Prime Movers | |
| 1125-1345 | Machine Shops and Machine Shops Practice | |
| 1350-1418 | Hoisting and Conveying Machinery | |
| 1425-1475 | Lifting and Pressing Machinery | |
| 1480-1496 | Agricultural Machinery, Farm Machines | |
| 1501-1519 | Sewing Machines | |
| TK | 1-9971 | Electrical Engineering, Electronics, Nuclear Engineering. |
| 301-399 | Electric Meters | |
| 452-454.4 | Electric Apparatus and Materials, Electric Circuits, Electric Networks | |
| 1001-1841 | Production of Electric Energy or Power, Powerplants, Central Stations | |
| 2000-2891 | Dynamoelectric Machinery and Auxiliaries (including generators, transformers, motors) | |
| 2896-2985 | Production of Electricity by Direct Electricity Conversion | |
| 3001-3521 | Distribution or Transmission of Electric Power | |
| 4001-4102 | Applications of Electric Power | |
| 4125-4399 | Electric Lighting | |
| 4601-4661 | Electric Heating | |
| 5101-6720 | Telecommunication (including telegraphy, telephone, radio, radar, television) | |
| 7800-8360 | Electronics | |
| 7885-7895 | Computer Engineering, Computer Hardware | |
| 8300-8360 | Photoelectronic Devices (General) | |
| 9001-9401 | Nuclear Engineering, Atomic Power | |
| 9900-9971 | Electricity for Amateurs, Amateur Constructors' Manuals | |
| TL | 1-4050 | Motor Vehicles, Aeronautics, Astronautics |
| 1-484 | Motor Vehicles, Cycles | |
| 500-777 | Aeronautics, Aeronautical Engineering | |
| 780-785.8 | Rockets | |
| 787-4050 | Astronautics, Space Travel | |
| TN | 1-997 | Mining Engineering, Metallurgy. |
| 165-205 | Study and Teaching | |
| 275-269 | Mineral Deposits, Metallic Ore Deposits | |
| 270-271 | Prospecting | |
| 275-325 | Practical Mining Operations, Safety Measures | |
| 400-580 | Ore Deposits and Mining of Particular Metals | |
| 600-799 | Metallurgy | |
| 799.5-948 | Nonmetallic Minerals | |
| 950-997 | Building and Ornamental Stones | |
| TP | 1-1185 | Chemical Technology. |
| 155-156 | Chemical Engineering | |
| 200-248 | Manufacture and Use of Chemicals | |
| 248.13-248.65 | Biotechnology | |
| 250-261 | Industrial Electrochemistry | |
| 267.5-301 | Explosives and Pyrotechnics | |
| 315-360 | Fuel | |
| 368-456 | Food Processing and Manufacture | |
| 480-498 | Low Temperature Engineering, Cyrogenic Engineering, Refrigeration | |
| 500-660 | Fermentation Industries, Beverages, Alcohol | |
| 670-699 | Oils, Fats, and Waxes | |
| 690-692.4 | Petroleum Refining and Products | |
| 751-762 | Gas Industry | |
| 785-869 | Ceramics, Clay Industries, Glass | |
| 875-888 | Cement Industries | |
| 890-933 | Textile Bleaching, Dyeing, Printing, etc. | |
| 934-945 | Paints, Pigments, Varnishes, etc. | |
| 1080-1185 | Polymers, Plastics | |
| TR | 1-1050 | Photography. |
| 250-265 | Cameras | |
| 287-500 | Photographic Processing | |
| 504-508 | Transparencies, Diapositives | |
| 510-545 | Color Photography | |
| 550-581 | Studio and Laboratory | |
| 590-620 | Lighting | |
| 624-835 | Applied Photography | |
| 845-899 | Cinematography, Motion Pictures | |
| 925-1050 | Photomechanical Processes | |
| TS | 1-2301 | Manufactures. |
| 155-194 | Production Management | |
| 195-198.8 | Packaging | |
| 200-770 | Metal Manufactures, Metalworking | |
| 780-788 | Stonework | |
| 800-937 | Wood Technology, Lumber | |
| 840-915 | Wood Products, Furniture | |
| 920-937 | Chemical Processing of Food | |
| 940-1047 | Leather Industries, Tanning | |
| 1080-1268 | Paper Manufacture and Trade, Woodpulp Industry | |
| 1300-1865 | Textile Industries | |
| 1870-1935 | Rubber Industry | |
| 1950-1982 | Animal Products | |
| 2120-2159 | Cereal, Grain and Flour, Milling Industry | |
| 2220-2283 | Tobacco Industry | |
| 2284-2288 | Animal Feeds and Feed Mills, Pet Food Industry | |
| TT | 1-999 | Arts and Crafts, Handicrafts. |
| 161-170.7 | Manual Training, Industrial Arts, School Shops | |
| 174-176 | Articles for Children | |
| 180-200 | Woodworking, Furniture Making, Upholstering | |
| 201-203 | Lathework, Turning | |
| 205-267 | Metalworking | |
| 300-382.8 | Painting, Industrial Painting, Wood Fininshing | |
| 387-410 | Soft Home Furnishings | |
| 490-695 | Clothing Manufacture, Dressmaking, Tailoring | |
| 697-927 | Home Arts, Home Crafts (including sewing, embroidery, decorative crafts) | |
| 950-979 | Hairdressing, Beauty Culture, Barbers' Work | |
| 980-999 | Laundry Work | |
| TX | 1-1107.4 | Home Economics. |
| 301-329 | The House: Logistics, Finance, Care | |
| 341-641 | Nutrition, Food and Food Supply | |
| 643-840 | Cookery | |
| 851-885 | Dining-Room Service | |
| 901-946.5 | Hospitality Industry, Hotels, Clubs, Restaurants, Food Service, etc. | |
| 950-953 | Taverns, Barrooms, Saloons | |
| 955-985 | Building Operation and Housekeeping | |
| 1100-1105 | Mobile Home Living | |
| 1110 | Recreational Vehicle Living |
To the Library of Congress Classification index
