# US 10,478,984 B2 · Chemically sharpening blades > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,478,984 B2 - Document ID: US10478984B2 - Status: Granted - Kind: B2 - Application number: 15/845,351 - Filed: 2017-12-18 - Published: 2018-04-19 - Granted: 2019-11-19 - Earliest claimed: 2015-03-02 - Assignees: Hutchinson Technology Incorporated - Applicants: Hutchinson Technology Incorporated - Inventors: Paul V. Pesavento; Peter F. Ladwig; Michael W. Davis; John A. Theget; Kurt C. Swanson; Joel B. Michaletz; Philip W. Anderson; Timothy A. McDaniel - Web page: https://patentgrep.com/patent/US10478984B2 ## CPC - B26D 1/0006: {Cutting members therefor} - B26B 9/00: Blades for hand knives - B26B 9/02: characterised by the shape of the cutting edge, e.g. wavy - C23F 1/04: Chemical milling - B26D 2001/0053: {having a special cutting edge section or blade section} - B26D: CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING (for growing crops or plants A01D, A01G; for fodder or straw A01F; for bulk butter A01J; for dough A21C; slaughtering A22B; for tobacco, cigars or cigarettes A24; marking-out, perforating or making buttonholes A41H25/00; manufacturing footwear A43D; brushmaking A46D; surgery A61B; disintegrating, mincing or shredding in general B02C; cutting wire, making pins or nails B21F, B21G; of the kind used formetal B23; cutting by abrasive fluid jets B24C5/02; hand-held cutting tools B26B; perforating, cutting-out, stamping-out or punching, or severing by means other than cutting B26F; for wood B27; for stone B28D; working of plastics or substances in a plastic state B29; making boxes, cartons, envelopes or bags, of paper or similarly worked materials, e.g. metal foil, B31B; article or web delivery apparatus incorporating cutting or line-perforating devices B65H35/00; for leather or upholstery B68, C14B; for glass C03B; making matches C06F; for peat C10F; for sugar C13B45/00; for textile materials D06H; civil engineering, building, mining, see Section E; for light guides G02B6/25; cutting processed photographic material G03D15/04) - B26B: HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR (for harvesting A01D; for horticulture, for forestry A01G; for butchering or meat treatment A22; for manufactering or repairing footwear A43D; nail clippers or cutters A45D29/02; kitchen equipment A47J; {vegetable slicers, julienne cutters and similar devices and holders therefor, B26D3/28}; for surgical purposes A61B; for metal B23D; cutting by abrasive fluid jets B24C5/02; plier-like tools with cutting edges B25B7/22; pincers B25C11/02; handles for hand implements, in general B25G; guillotine-type cutters B26D; {perforating by non-mechanical means, e.g. by fluid jet, B26F1/26}; for erasing B43L19/00; for textile materials D06H) - C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25 ## Abstract A method for forming a cutting tool includes masking a metal base with one or more masks, the one or more masks including at least one variable permeability mask, and chemically etching the masked metal base to form a blade of the cutting tool. ## Claims ### Claim 1 A method for forming a metal base, the method comprising applying a first mask and a second mask to a first side of the metal base to form a first window between the first mask and the second mask; applying a third mask and a fourth mask to a second side of the metal base to form a second window between the third mask and the fourth mask; applying a first variable permeability mask adjacent to the third mask of the second side of the metal base; and chemically etching the metal base at the first window and the second window in a first stage to form a first void on the first side and a second void on the second side. ### Claim 2 (depends on 1) The method of claim 1, wherein the first variable permeability mask is in contact with the third mask. ### Claim 3 (depends on 1) The method of claim 1, wherein the first variable permeability mask is continuous with the third mask. ### Claim 4 (depends on 1) The method of claim 1, further comprising applying a fifth mask to cover the second side of the metal base including the second void. ### Claim 5 (depends on 4) The method of claim 4, wherein the first void includes a trench which will isolate a residual end of the metal base for removal in the second etching stage. ### Claim 6 (depends on 4) The method of claim 4, further comprising applying a sixth mask on the first side of the metal base and a second variable permeability mask adjacent to the sixth mask. ### Claim 7 (depends on 6) The method of claim 6, wherein the second variable permeability mask is located between the sixth mask and the first void. ### Claim 8 (depends on 7) The method of claim 7, wherein a space between the second variable permeability mask and the first void is larger than the second variable permeability mask. ### Claim 9 (depends on 6) The method of claim 6, further comprising chemically etching the first void to create a blade surface in the metal base with an inflection point defined by a juncture of a distal convex portion and a proximal concave portion. ### Claim 10 (depends on 9) The method of claim 9, wherein chemically etching the first void of the metal base removes material from only the first side of the metal base. ### Claim 11 (depends on 9) The method of claim 9, wherein chemically etching the first void of the metal base includes forming a blade to include two bevels, the two bevels being located on the top and bottom sides of the blade, respectively. ### Claim 12 (depends on 1) The method of claim 1, wherein chemically etching the metal base removes material from both of the first side and the second side of the metal base.