| Patents for none listed |
Patents 556 -
570
of 3142
      |
| Number | Date | Patentee | Title | Type |
| D57,394 | Mar. 15, 1921 | C.E. Swihart | Combination Tool | pliers |
| 1,371,350 | Mar. 15, 1921 | S.A. Campbell | Wrench | socket wrenches |
| 1,371,617 | Mar. 15, 1921 | H. Germanow | Combination-Vise | toolmakers vises |
| 1,371,965 | Mar. 15, 1921 | P. York | Port Plug Wrench | automotive specialty wrenches |
| 1,372,433 | Mar. 22, 1921 | F. Janusch | Vernier Surface Gage | surface gauges |
| D57,548 | Apr. 12, 1921 | A.H. Starrett | Design for a prick-punch, nail-set, or article of similar nature | punches |
| 1,375,530 | Apr. 19, 1921 | C.G. Moline | Wrench | screw adjust wrenches |
| 1,375,747 | Apr. 26, 1921 | M. Zigray | Rivet Gage | special purpose gauges |
| 1,376,583 | May 03, 1921 | H.G. Rice | Bottle Capper | bottle cappers |
| 1,378,209 | May 17, 1921 | J.E. Bergman | Wrench | nut wrenches |
| D57,987 | May 24, 1921 | C.W. Manzel | Grease Gun | grease guns |
| 1,380,566 | Jun. 07, 1921 | A.W. Kiefer | Pipe Wrench | pipe wrenches |
| 1,381,457 | Jun. 14, 1921 | M.H. Derringer | Tool Holder | lathe tool holders and tool posts |
| 1,382,320 | Jun. 21, 1921 | C. Yunker, E. Riley | Bolt and Nut Holder | socket wrenches |
| 1,382,611 | Jun. 28, 1921 | B.F. Augustine | Rotary Gas Engine | rotary engines |
