# Library of Congress Classification/Class T

CLASS T - TECHNOLOGY
(Click each subclass for details)
| Subclass T | Technology (General) |
| Subclass TA | Engineering (General). Civil engineering |
| Subclass TC | Hydraulic engineering. Ocean engineering |
| Subclass TD | Environmental technology. Sanitary engineering |
| Subclass TE | Highway engineering. Roads and pavements |
| Subclass TF | Railroad engineering and operation |
| Subclass TG | Bridge engineering |
| Subclass TH | Building construction |
| Subclass TJ | Mechanical engineering and machinery |
| Subclass TK | Electrical engineering. Electronics. Nuclear engineering |
| Subclass TL | Motor vehicles. Aeronautics. Astronautics |
| Subclass TN | Mining engineering. Metallurgy |
| Subclass TP | Chemical technology |
| Subclass TR | Photography |
| Subclass TS | Manufactures |
| Subclass TT | Handicrafts. Arts and crafts |
| Subclass TX | Home economics |
​Subclass T
| T1-995 | Technology (General) | Technology (General) | Technology (General) |
| T10.5-11.9 | Communication of technical information | Communication of technical information | Communication of technical information |
| T11.95-12.5 | Industrial directories | Industrial directories | Industrial directories |
| T55-55.3 | | Industrial safety. Industrial accident prevention | Industrial safety. Industrial accident prevention |
| T55.4-60.8 | Industrial engineering. Management engineering | Industrial engineering. Management engineering | Industrial engineering. Management engineering |
| T57-57.97 | | Applied mathematics. Quantitative methods | Applied mathematics. Quantitative methods |
| T57.6-57.97 | | | Operations research. Systems analysis |
| T58.4 | | Managerial control systems | Managerial control systems |
| T58.5-58.64 | | Information technology | Information technology |
| T58.6-58.62 | | Management information systems | Management information systems |
| T58.7-58.8 | | Production capacity. Manufacturing capacity | Production capacity. Manufacturing capacity |
| T59-59.2 | | Standardization | Standardization |
| T59.5 | | Automation | Automation |
| T59.7-59.77 | | Human engineering in industry. Man-machine systems | Human engineering in industry. Man-machine systems |
| T60-60.8 | | Work measurement. Methods engineering | Work measurement. Methods engineering |
| T61-173 | Technical education. Technical schools | Technical education. Technical schools | Technical education. Technical schools |
| T173.2-174.5 | Technological change | Technological change | Technological change |
| T175-178 | Industrial research. Research and development | Industrial research. Research and development | Industrial research. Research and development |
| T201-342 | Patents. Trademarks | Patents. Trademarks | Patents. Trademarks |
| T351-385 | Mechanical drawing. Engineering graphics | Mechanical drawing. Engineering graphics | Mechanical drawing. Engineering graphics |
| T391-995 | Exhibitions. Trade shows. World's fairs | Exhibitions. Trade shows. World's fairs | Exhibitions. Trade shows. World's fairs |
| TA1-2040 | Engineering (General). Civil engineering (General) |
| TA164 | Bioengineering |
| TA165 | Engineering instruments, meters, etc. Industrial instrumentation |
| TA166-167 | Human engineering |
| TA168 | Systems engineering |
| TA170-171 | Environmental engineering |
| TA174 | Engineering design |
| TA177.4-185 | Engineering economy |
| TA190-194 | Management of engineering works |
| TA197-198 | Engineering meteorology |
| TA213-215 | Engineering machinery, tools, and implements |
| TA329-348 | Engineering mathematics. Engineering analysis |
| TA349-359 | Mechanics of engineering. Applied mechanics |
| TA365-367 | Acoustics in engineering. Acoustical engineering |
| TA401-492 | Materials of engineering and construction. Mechanics of materials |
| TA495 | Disasters and engineering |
| TA501-625 | Surveying |
| TA630-695 | Structural engineering (General) |
| TA703-712 | Engineering geology. Rock mechanics. Soil mechanics. Underground construction |
| TA715-787 | Earthwork. Foundations |
| TA800-820 | Tunneling. Tunnels |
| TA1001-1280 | Transportation engineering |
| TA1501-1820 | Applied optics. Photonics |
| TA2001-2040 | Plasma engineering. Applied plasma dynamics |
| TC1-978 | Hydraulic engineering | Hydraulic engineering |
| TC160-181 | | Technical hydraulics |
| TC183-201 | | General preliminary operations. Dredging. Submarine building |
| TC203-380 | | Harbors and coast protective works. Coastal engineering. Lighthouses |
| TC401-506 | | River, lake, and water-supply engineering (General) |
| TC530-537 | | River protective works. Regulation. Flood control |
| TC540-558 | | Dams. Barrages |
| TC601-791 | | Canals and inland navigation. Waterways |
| TC801-978 | | Irrigation engineering. Reclamation of wasteland. Drainage |
| TC1501-1800 | Ocean engineering | Ocean engineering |
| TD1-1066 | Environmental technology. Sanitary engineering | Environmental technology. Sanitary engineering |
| TD159-168 | Municipal engineering | Municipal engineering |
| TD169-171.8 | Environmental protection | Environmental protection |
| TD172-193.5 | Environmental pollution | Environmental pollution |
| TD194-195 | Environmental effects of industries and plants | Environmental effects of industries and plants |
| TD201-500 | Water supply for domestic and industrial purposes | Water supply for domestic and industrial purposes |
| TD419-428 | | Water pollution |
| TD429.5-480.7 | | Water purification. Water treatment and conditioning. Saline water conversion |
| TD481-493 | | Water distribution systems |
| TD511-780 | Sewage collection and disposal systems. Sewerage | Sewage collection and disposal systems. Sewerage |
| TD783-812.5 | Municipal refuse. Solid wastes | Municipal refuse. Solid wastes |
| TD813-870 | Street cleaning. Litter and its removal | Street cleaning. Litter and its removal |
| TD878-894 | Special types of environment Including soil pollution, air pollution, noise pollution | Special types of environment Including soil pollution, air pollution, noise pollution |
| TD895-899 | Industrial and factory sanitation | Industrial and factory sanitation |
| TD896-899 | | Industrial and factory wastes |
| TD920-934 | Rural and farm sanitary engineering | Rural and farm sanitary engineering |
| TD940-949 | Low temperature sanitary engineering | Low temperature sanitary engineering |
| TD1020-1066 | Hazardous substances and their disposal | Hazardous substances and their disposal |
| TE1-450 | Highway engineering. Roads and pavements | Highway engineering. Roads and pavements |
| TE175-176.5 | Highway design. Interchanges and intersections | Highway design. Interchanges and intersections |
| TE177-178.8 | Roadside development. Landscaping | Roadside development. Landscaping |
| TE200-205 | Materials for roadmaking | Materials for roadmaking |
| TE206-209.5 | Location engineering | Location engineering |
| TE210-228.3 | Construction details Including foundations, maintenance, equipment | Construction details Including foundations, maintenance, equipment |
| TE250-278.8 | Pavements and paved roads | Pavements and paved roads |
| TE279 | Streets | Streets |
| TE279.5-298 | Pedestrian facilities | Pedestrian facilities |
| TE280-295 | | Sidewalks. Footpaths. Flagging |
| TE298 | | Curbs. Curbstones |
| TF1-1620 | Railroad engineering and operation | Railroad engineering and operation |
| TF200-320 | Railway construction | Railway construction |
| TF340-499 | Railway equipment and supplies | Railway equipment and supplies |
| TF501-668 | Railway operation and management | Railway operation and management |
| TF670-851 | Local and light railways | Local and light railways |
| TF840-851 | | Elevated railways and subways |
| TF855-1127 | Electric railways | Electric railways |
| TF1300-1620 | High speed ground transporation | High speed ground transporation |
| TG1-470 | Bridge engineering |
| TH1-9745 | Building construction |
| TH845-895 | Architectural engineering. Structural engineering of buildings |
| TH900-915 | Construction equipment in building |
| TH1000-1725 | Systems of building construction Including fireproof construction, concrete construction |
| TH2025-3000 | Details in building design and construction Including walls, roofs |
| TH3301-3411 | Maintenance and repair |
| TH4021-4977 | Buildings: Construction with reference to use Including public buildings, dwellings |
| TH5011-5701 | Construction by phase of the work (Building trades) |
| TH6014-6081 | Environmental engineering of buildings. Sanitary engineering of buildings |
| TH6101-6887 | Plumbing and pipefitting |
| TH7005-7699 | Heating and ventilation. Air conditioning |
| TH7700-7975 | Illumination. Lighting |
| TH8001-8581 | Decoration and decorative furnishings |
| TH9025-9745 | Protection of buildings Including protection from dampness, fire, burglary |
| TJ1-1570 | Mechanical engineering and machinery | Mechanical engineering and machinery |
| TJ163.13-163.25 | Power resources | Power resources |
| TJ163.26-163.5 | Energy conservation | Energy conservation |
| TJ170-179 | Mechanics applied to machinery. Dynamics | Mechanics applied to machinery. Dynamics |
| TJ181-210 | Mechanical movements | Mechanical movements |
| TJ210.2-211.47 | Mechanical devices and figures. Automata. Ingenious mechanisms. Robots (General) | Mechanical devices and figures. Automata. Ingenious mechanisms. Robots (General) |
| TJ212-225 | Control engineering systems. Automatic machinery (General) | Control engineering systems. Automatic machinery (General) |
| TJ227-240 | Machine design and drawing | Machine design and drawing |
| TJ241-254.7 | Machine construction (General) | Machine construction (General) |
| TJ255-265 | Heat engines | Heat engines |
| TJ266-267.5 | Turbines. Turbomachines (General) | Turbines. Turbomachines (General) |
| TJ268-740 | Steam engineering | Steam engineering |
| TJ603-695 | | Locomotives |
| TJ751-805 | Miscellaneous motors and engines Including gas, gasoline, diesel engines | Miscellaneous motors and engines Including gas, gasoline, diesel engines |
| TJ807-830 | Renewable energy sources | Renewable energy sources |
| TJ836-927 | Hydraulic machinery | Hydraulic machinery |
| TJ940-940.5 | Vacuum technology | Vacuum technology |
| TJ950-1030 | Pneumatic machinery | Pneumatic machinery |
| TJ1040-1119 | Machinery exclusive of prime movers | Machinery exclusive of prime movers |
| TJ1125-1345 | Machine shops and machine shop practice | Machine shops and machine shop practice |
| TJ1350-1418 | Hoisting and conveying machinery | Hoisting and conveying machinery |
| TJ1425-1475 | Lifting and pressing machinery | Lifting and pressing machinery |
| TJ1480-1496 | Agricultural machinery. Farm machinery | Agricultural machinery. Farm machinery |
| TJ1501-1519 | Sewing machines | Sewing machines |
| TK1-9971 | Electrical engineering. Electronics. Nuclear engineering | Electrical engineering. Electronics. Nuclear engineering |
| TK301-399 | Electric meters | Electric meters |
| TK452-454.4 | Electric apparatus and materials. Electric circuits. Electric networks | Electric apparatus and materials. Electric circuits. Electric networks |
| TK1001-1841 | Production of electric energy or power. Powerplants. Central stations | Production of electric energy or power. Powerplants. Central stations |
| TK2000-2891 | Dynamoelectric machinery and auxiliaries Including generators, motors, transformers | Dynamoelectric machinery and auxiliaries Including generators, motors, transformers |
| TK2896-2985 | Production of electricity by direct energy conversion | Production of electricity by direct energy conversion |
| TK3001-3521 | Distribution or transmission of electric power | Distribution or transmission of electric power |
| TK4001-4102 | Applications of electric power | Applications of electric power |
| TK4125-4399 | Electric lighting | Electric lighting |
| TK4601-4661 | Electric heating | Electric heating |
| TK5101-6720 | Telecommunication Including telegraphy, telephone, radio, radar, television | Telecommunication Including telegraphy, telephone, radio, radar, television |
| TK7800-8360 | Electronics | Electronics |
| TK7885-7895 | | Computer engineering. Computer hardware |
| TK8300-8360 | | Photoelectronic devices (General) |
| TK9001-9401 | Nuclear engineering. Atomic power | Nuclear engineering. Atomic power |
| TK9900-9971 | Electricity for amateurs. Amateur constructors' manuals | Electricity for amateurs. Amateur constructors' manuals |
| TL1-4050 | Motor vehicles. Aeronautics. Astronautics |
| TL1-484 | Motor vehicles. Cycles |
| TL500-777 | Aeronautics. Aeronautical engineering |
| TL780-785.8 | Rocket propulsion. Rockets |
| TL787-4050 | Astronautics. Space travel |
| TN1-997 | Mining engineering. Metallurgy |
| TN263-271 | Mineral deposits. Metallic ore deposits. Prospecting |
| TN275-325 | Practical mining operations. Safety measures |
| TN331-347 | Mine transportation, haulage and hoisting. Mining machinery |
| TN400-580 | Ore deposits and mining of particular metals |
| TN600-799 | Metallurgy |
| TN799.5-948 | Nonmetallic minerals |
| TN950-997 | Building and ornamental stones |
| TP1-1185 | Chemical technology | Chemical technology |
| TP155-156 | Chemical engineering | Chemical engineering |
| TP200-248 | Chemicals: Manufacture, use, etc. | Chemicals: Manufacture, use, etc. |
| TP248.13-248.65 | Biotechnology | Biotechnology |
| TP250-261 | Industrial electrochemistry | Industrial electrochemistry |
| TP267.5-301 | Explosives and pyrotechnics | Explosives and pyrotechnics |
| TP315-360 | Fuel | Fuel |
| TP368-456 | Food processing and manufacture | Food processing and manufacture |
| TP480-498 | Low temperature engineering. Cryogenic engineering. Refrigeration | Low temperature engineering. Cryogenic engineering. Refrigeration |
| TP500-660 | Fermentation industries. Beverages. Alcohol | Fermentation industries. Beverages. Alcohol |
| TP670-699 | Oils, fats, and waxes | Oils, fats, and waxes |
| TP690-692.5 | | Petroleum refining. Petroleum products |
| TP700-746 | Illuminating industries (Nonelectric) | Illuminating industries (Nonelectric) |
| TP751-762 | Gas industry | Gas industry |
| TP785-869 | Clay industries. Ceramics. Glass | Clay industries. Ceramics. Glass |
| TP875-888 | Cement industries | Cement industries |
| TP890-933 | Textile bleaching, dyeing, printing, etc. | Textile bleaching, dyeing, printing, etc. |
| TP934-945 | Paints, pigments, varnishes, etc. | Paints, pigments, varnishes, etc. |
| TP1080-1185 | Polymers and polymer manufacture | Polymers and polymer manufacture |
| TR1-1050 | Photography |
| TR250-265 | Cameras |
| TR287-500 | Photographic processing. Darkroom technique |
| TR504-508 | Transparencies. Diapositives |
| TR510-545 | Color photography |
| TR550-581 | Studio and laboratory |
| TR590-620 | Lighting |
| TR624-835 | Applied photography Including artistic, commercial, medical photography, photocopying processes |
| TR845-899 | Cinematography. Motion pictures |
| TR925-1050 | Photomechanical processes |
| TS1-2301 | Manufactures | Manufactures |
| TS155-194 | Production management. Operations management | Production management. Operations management |
| TS195-198.8 | Packaging | Packaging |
| TS200-770 | Metal manufactures. Metalworking | Metal manufactures. Metalworking |
| TS780-788 | Stonework | Stonework |
| TS800-937 | Wood technology. Lumber | Wood technology. Lumber |
| TS840-915 | | Wood products. Furniture |
| TS920-937 | | Chemical processing of wood |
| TS940-1047 | Leather industries. Tanning | Leather industries. Tanning |
| TS1060-1070 | Furs | Furs |
| TS1080-1268 | Paper manufacture and trade | Paper manufacture and trade |
| TS1300-1865 | Textile industries | Textile industries |
| TS1870-1935 | Rubber industry | Rubber industry |
| TS1950-1982 | Animal products | Animal products |
| TS2120-2159 | Cereals and grain. Milling industry | Cereals and grain. Milling industry |
| TS2220-2283 | Tobacco industry | Tobacco industry |
| TS2284-2288 | Animal feeds and feed mills. Pet food industry | Animal feeds and feed mills. Pet food industry |
| TT1-999 | Handicrafts. Arts and crafts |
| TT161-170.7 | Manual training. School shops |
| TT174-176 | Articles for children |
| TT180-200 | Woodworking. Furniture making. Upholstering |
| TT201-203 | Lathework. Turning |
| TT205-267 | Metalworking |
| TT300-382.8 | Painting. Wood finishing |
| TT387-410 | Soft home furnishings |
| TT490-695 | Clothing manufacture. Dressmaking. Tailoring |
| TT697-927 | Home arts. Homecrafts Including sewing, embroidery, decorative crafts |
| TT950-979 | Hairdressing. Beauty culture. Barbers' work |
| TT980-999 | Laundry work |
| TX1-1110 | Home economics |
| TX301-339 | The house Including arrangement, care, servants |
| TX341-641 | Nutrition. Foods and food supply |
| TX642-840 | Cooking |
| TX851-885 | Dining-room service |
| TX901-946.5 | Hospitality industry. Hotels, clubs, restaurants, etc. Food service |
| TX950-953 | Taverns, barrooms, saloons |
| TX955-985 | Building operation and housekeeping |
| TX1100-1105 | Mobile home living |
| TX1110 | Recreational vehicle living |