| Class Num. | Count | Class Description |
| 424 | 1638 | Drug, bio-affecting and body treating compositions |
| 514 | 1624 | Drug, bio-affecting and body treating compositions |
| 435 | 1063 | Chemistry: molecular biology and microbiology |
| 510 | 563 | Cleaning compositions for solid surfaces, auxiliary compositions therefor, or pr |
| 623 | 415 | Prosthesis (i.e., artificial body members), parts thereof, or aids and accessori |
| 606 | 358 | Surgery |
| 604 | 280 | Surgery |
| 428 | 275 | Stock material or miscellaneous articles |
| 536 | 233 | Organic compounds -- part of the class 532-570 series |
| 530 | 221 | Chemistry: natural resins or derivatives; peptides or proteins; lignins or react |
| 210 | 211 | Liquid purification or separation |
| 528 | 187 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 430 | 159 | Radiation imagery chemistry: process, composition, or product thereof |
| 600 | 137 | Surgery |
| 525 | 117 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 524 | 111 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 264 | 106 | Plastic and nonmetallic article shaping or treating: processes |
| 47 | 91 | Plant husbandry |
| 134 | 79 | Cleaning and liquid contact with solids |
| 523 | 79 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 427 | 78 | Coating processes |
| 8 | 74 | Bleaching and dyeing; fluid treatment and chemical modification of textiles and |
| 508 | 74 | Solid anti-friction devices, materials therefor, lubricant or separant compositi |
| 252 | 69 | Compositions |
| 800 | 68 | Multicellular living organisms and unmodified parts thereof and related processe |
| 162 | 68 | Paper making and fiber liberation |
| 106 | 63 | Compositions: coating or plastic |
| 422 | 59 | Chemical apparatus and process disinfecting, deodorizing, preserving, or sterili |
| 493 | 58 | Manufacturing container or tube from paper; or other manufacturing from a sheet |
| 426 | 58 | Food or edible material: processes, compositions, and products |
| 128 | 56 | Surgery |
| 405 | 50 | Hydraulic and earth engineering |
| 206 | 47 | Special receptacle or package |
| 521 | 44 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 504 | 43 | Plant protecting and regulating compositions |
| 156 | 40 | Adhesive bonding and miscellaneous chemical manufacture |
| 119 | 37 | Animal husbandry |
| 562 | 37 | Organic compounds -- part of the class 532-570 series |
| 507 | 35 | Earth boring, well treating, and oil field chemistry |
| 526 | 34 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 53 | 32 | Package making |
| 554 | 30 | Organic compounds -- part of the class 532-570 series |
| 166 | 30 | Wells |
| 546 | 28 | Organic compounds -- part of the class 532-570 series |
| 71 | 28 | Chemistry: fertilizers |
| 516 | 28 | Colloid systems and wetting agents; subcombinations thereof; processes of |
| 442 | 28 | Fabric (woven, knitted, or nonwoven textile or cloth, etc.) |
| 585 | 26 | Chemistry of hydrocarbon compounds |
| 43 | 25 | Fishing, trapping, and vermin destroying |
| 607 | 25 | Surgery: light, thermal, and electrical application |
| 229 | 25 | Envelopes, wrappers, and paperboard boxes |
| 560 | 25 | Organic compounds -- part of the class 532-570 series |
| 549 | 24 | Organic compounds -- part of the class 532-570 series |
| 588 | 22 | Hazardous or toxic waste destruction or containment |
| 4 | 20 | Baths, closets, sinks, and spittoons |
| 436 | 20 | Chemistry: analytical and immunological testing |
| 548 | 18 | Organic compounds -- part of the class 532-570 series |
| 241 | 18 | Solid material comminution or disintegration |
| 568 | 17 | Organic compounds -- part of the class 532-570 series |
| 205 | 17 | Electrolysis: processes, compositions used therein, and methods of preparing the |
| 220 | 16 | Receptacles |
| 564 | 16 | Organic compounds -- part of the class 532-570 series |
| 433 | 16 | Dentistry |
| 544 | 14 | Organic compounds -- part of the class 532-570 series |
| 451 | 14 | Abrading |
| 52 | 14 | Static structures (e.g., buildings) |
| 558 | 13 | Organic compounds -- part of the class 532-570 series |
| 44 | 12 | Fuel and related compositions |
| 204 | 12 | Chemistry: electrical and wave energy |
| 552 | 12 | Organic compounds -- part of the class 532-570 series |
| 602 | 12 | Surgery: splint, brace, or bandage |
| 2 | 11 | Apparel |
| 294 | 11 | Handling: hand and hoist-line implements |
| 131 | 11 | Tobacco |
| 62 | 11 | Refrigeration |
| 502 | 10 | Catalyst, solid sorbent, or support therefor: product or process of making |
| 242 | 10 | Winding, tensioning, or guiding |
| 15 | 10 | Brushing, scrubbing, and general cleaning |
| 501 | 10 | Compositions: ceramic |
| 540 | 10 | Organic compounds -- part of the class 532-570 series |
| 425 | 10 | Plastic article or earthenware shaping or treating: apparatus |
| 34 | 9 | Drying and gas or vapor contact with solids |
| 102 | 9 | Ammunition and explosives |
| 522 | 9 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 222 | 8 | Dispensing |
| 261 | 8 | Gas and liquid contact apparatus |
| 250 | 8 | Radiant energy |
| 401 | 8 | Coating implements with material supply |
| 209 | 8 | Classifying, separating, and assorting solids |
| 219 | 8 | Electric heating |
| 423 | 8 | Chemistry of inorganic compounds |
| 124 | 8 | Mechanical guns and projectors |
| 114 | 8 | Ships |
| 118 | 7 | Coating apparatus |
| 473 | 7 | Games using tangible projectile |
| 73 | 7 | Measuring and testing |
| 446 | 7 | Amusement devices: toys |
| 175 | 7 | Boring or penetrating the earth |
| 29 | 6 | Metal working |
| 239 | 6 | Fluid sprinkling, spraying, and diffusing |
| 221 | 6 | Article dispensing |
| 111 | 6 | Planting |
| 556 | 6 | Organic compounds -- part of the class 532-570 series |
| 347 | 6 | Incremental printing of symbolic information |
| 149 | 6 | Explosive and thermic compositions or charges |
| 127 | 6 | Sugar, starch, and carbohydrates |
| 75 | 6 | Specialized metallurgical processes, compositions for use therein, consolidated |
| 55 | 5 | Gas separation |
| 169 | 5 | Fire extinguishers |
| 216 | 5 | Etching a substrate: processes |
| 174 | 5 | Electricity: conductors and insulators |
| 396 | 5 | Photography |
| 361 | 5 | Electricity: electrical systems and devices |
| 95 | 5 | Gas separation: processes |
| 248 | 5 | Supports |
| 108 | 5 | Horizontally supported planar surfaces |
| 100 | 5 | Presses |
| 137 | 5 | Fluid handling |
| 24 | 5 | Buckles, buttons, clasps, etc. |
| 438 | 5 | Semiconductor device manufacturing: process |
| 5 | 5 | Beds |
| 27 | 5 | Undertaking |
| 116 | 4 | Signals and indicators |
| 512 | 4 | Perfume compositions |
| 208 | 4 | Mineral oils: processes and products |
| 141 | 4 | Fluent material handling, with receiver or receiver coacting means |
| 359 | 4 | Optical: systems and elements |
| 51 | 3 | Abrasive tool making process, material, or composition |
| 91 | 3 | Motors: expansible chamber type |
| 237 | 3 | Heating systems |
| 434 | 3 | Education and demonstration |
| 83 | 3 | Cutting |
| 702 | 3 | Data processing: measuring, calibrating, or testing |
| 60 | 3 | Power plants |
| 383 | 3 | Flexible bags |
| 139 | 3 | Textiles: weaving |
| 68 | 3 | Textiles: fluid treating apparatus |
| 132 | 3 | Toilet |
| 184 | 3 | Lubrication |
| 138 | 2 | Pipes and tubular conduits |
| 366 | 2 | Agitating |
| 503 | 2 | Record receiver having plural interactive leaves or a colorless color former, me |
| 527 | 2 | Synthetic resins or natural rubbers -- part of the class 520 series |
| 235 | 2 | Registers |
| 472 | 2 | Amusement devices |
| 223 | 2 | Apparel apparatus |
| 384 | 2 | Bearings |
| 356 | 2 | Optics: measuring and testing |
| 181 | 2 | Acoustics |
| 99 | 2 | Foods and beverages: apparatus |
| 367 | 2 | Communications, electrical: acoustic wave systems and devices |
| 101 | 2 | Printing |
| 418 | 2 | Rotary expansible chamber devices |
| 700 | 2 | Data processing: generic control systems or specific applications |
| 224 | 2 | Package and article carriers |
| 164 | 2 | Metal founding |
| 30 | 2 | Cutlery |
| 419 | 2 | Powder metallurgy processes |
| 340 | 2 | Communications: electrical |
| 96 | 2 | Gas separation: apparatus |
| 193 | 2 | Conveyors, chutes, skids, guides, and ways |
| 280 | 2 | Land vehicles |
| 432 | 2 | Heating |
| 42 | 2 | Firearms |
| 406 | 2 | Conveyors: fluid current |
| 358 | 2 | Facsimile and static presentation processing |
| 273 | 2 | Amusement devices: games |
| 376 | 2 | Induced nuclear reactions: processes, systems, and elements |
| 411 | 2 | Expanded, threaded, driven, headed, tool-deformed, or locked-threaded fastener |
| 112 | 1 | Sewing |
| 49 | 1 | Movable or removable closures |
| 351 | 1 | Optics: eye examining, vision testing and correcting |
| 12 | 1 | Boot and shoe making |
| 441 | 1 | Buoys, rafts, and aquatic devices |
| 455 | 1 | Telecommunications |
| 36 | 1 | Boots, shoes, and leggings |
| 123 | 1 | Internal-combustion engines |
| 56 | 1 | Harvesters |
| 379 | 1 | Telephonic communications |
| 342 | 1 | Communications: directive radio wave systems and devices (e.g., radar, radio nav |
| 269 | 1 | Work holders |
| 300 | 1 | Brush, broom, and mop making |
| 57 | 1 | Textiles: spinning, twisting, and twining |
| 290 | 1 | Prime-mover dynamo plants |
| 324 | 1 | Electricity: measuring and testing |
| 299 | 1 | Mining or in situ disintegration of hard material |
| 313 | 1 | Electric lamp and discharge devices |
| 378 | 1 | X-ray or gamma ray systems or devices |
| 310 | 1 | Electrical generator or motor structure |
| 256 | 1 | Fences |
| 452 | 1 | Butchering |
| 450 | 1 | Foundation garments |
| 431 | 1 | Combustion |
| 706 | 1 | Data processing: artificial intelligence |
| 460 | 1 | Crop threshing or separating |
| 122 | 1 | Liquid heaters and vaporizers |
| 404 | 1 | Road structure, process, or apparatus |
| 429 | 1 | Chemistry: electrical current producing apparatus, product, and process |
| 518 | 1 | Chemistry: fischer-tropsch processes; or purification or recovery of products th |
| 177 | 1 | Weighing scales |
| 414 | 1 | Material or article handling |
| 28 | 1 | Textiles: manufacturing |
| 227 | 1 | Elongated-member-driving apparatus |
| 392 | 1 | Electric resistance heating devices |
| 152 | 1 | Resilient tires and wheels |
| 201 | 1 | Distillation: processes, thermolytic |
| 440 | 1 | Marine propulsion |
| 66 | 1 | Textiles: knitting |
| 291 | 1 | Track sanders |
| 386 | 1 | Television signal processing for dynamic recording or reproducing |
| 148 | 1 | Metal treatment |
| 172 | 1 | Earth working |
| 410 | 1 | Freight accommodation on freight carrier |
| 449 | 1 | Bee culture |
| 228 | 1 | Metal fusion bonding |
| 159 | 1 | Concentrating evaporators |
| 415 | 1 | Rotary kinetic fluid motors or pumps |
| 202 | 1 | Distillation: apparatus |
| 23 | 1 | Chemistry: physical processes |
| 125 | 1 | Stone working |
| 534 | 1 | Organic compounds -- part of the class 532-570 series |
| 135 | 1 | Tent, canopy, umbrella, or cane |
| 277 | 1 | Seal for a joint or juncture |
| 249 | 1 | Static molds |
| 136 | 1 | Batteries: thermoelectric and photoelectric |
| 65 | 1 | Glass manufacturing |
| 343 | 1 | Communications: radio wave antennas |
| 385 | 1 | Optical waveguides |