Abstract: This invention relates to a novel application of liquid-infused surface materials (LISM) to at least a portion of one or more surfaces of razor components (e.g., frame, housing, clips, blade supports, blade body, blade edge, lubricating bodies, guard, handle, grip, button). If applied to a skin contacting surface of a component, the one or more LISM layers may generally be abrasion-resistant, long-lasting or non-erodible, desirably elevating shaving performance, such as glide, comfort, rinsing, and cleanliness, while also simplifying the manufacturing process.

Abstract: A low friction, wear-resistant surface operable at high temperatures and high loads with a low coefficient of friction including boron nitride and graphene-oxide on steel or nanodiamonds and graphene on aluminum. The low friction, wear-resistant surface remains with a coefficient of friction in the superlubric regime at temperatures in between about 200° C. and 970° C.

Abstract: A method of modifying razor blade edges prior to a first use, the method comprising providing at least one razor blade having a coated razor blade edge, and mechanically modifying at least one coating of said coated razor blade edge. Also provided is an apparatus for modifying one or more coated razor blade edges, the apparatus comprising a support member for holding a plurality of razor blades with said coated razor blade edges, and an applicator for contacting a mechanical modifying material with at least a section of said coated razor blade edges.

Abstract: This invention relates to a novel application of liquid-infused surface materials (LISM) to at least a portion of one or more surfaces of razor components (e.g., frame, housing, clips, blade supports, blade body, blade edge, lubricating bodies, guard, handle, grip, button). If applied to a skin contacting surface of a component, the one or more LISM layers may generally be abrasion-resistant, long-lasting or non-erodible, desirably elevating shaving performance, such as glide, comfort, rinsing, and cleanliness, while also simplifying the manufacturing process.

Abstract: A razor blade comprising a blade substrate with a blade edge substrate portion ending in blade tip. The razor blade is covered by a strengthening coating deposited on the blade edge substrate portion via a deposition process. The deposition process causes a hardness value of the strengthening coating layer to be increased, which, among other factors, allows for a decreased thickness of the blade substrate with coating. The blade substrate with coating has (i) a thickness of between about 1.57 and 2.37 micrometers measured at a distance of about five micrometers from the coating tip, (ii) a thickness of between about 4.62 and 6.74 micrometers measured at a distance of about twenty micrometers from the coating tip, and (iii) a thickness of between about 19.82 and 27.52 micrometers measured at a distance of about one hundred micrometers from the coating tip.

Abstract: The present invention relates to a razor blade having one or more coatings formed by the atomic layer deposition (ALD) process, the formed coatings being uniform, conformal, and dense. The coatings may be on an entire surface of a blade flank, and at least a portion or an entire surface of a blade body. The coatings may be etched. The invention relates to a razor blade having a first coating of a first material and a second coating of a second material where at least one of the first and second coatings is deposited using an ALD process and the second coating is deposited on a top surface of the first coating. The first and second materials may be similar or different. The present invention relates to a razor component having one coating of at least one layer of one or more materials formed using an ALD process.

Abstract: A ceramic cutting tool may include a blade body including zirconium oxide as a primary component of the blade body, wherein the blade body includes particles including any one of aluminum oxide, silicon carbide, or silicon nitride as a primary component of the particles, and wherein the blade body includes a blade part, a plurality of the particles are partially embedded and exposed on a top part of the blade part, and wherein the plurality of the particles cohere to each other to form a plurality of aggregates.

Abstract: A razor blade having an improved lubricious material deposited thereon and a method of making a razor blade for a razor cartridge having such a material disposed thereon are described herein. A novel printing process and printing material are provided where at least one printing material is deposited on one or more razor blades via a printing process which includes one or more print heads for printing the at least one printing material and forming at least one printed object on a tip or one or more sides of the razor blade. The printing material may comprise about of about 0.25% solid to about 50% solids by weight of composition of telomer and further desirably comprises glycerol and/or an antifoam material. Optimizing coverage of the printing material may be achieved by changing materials, print heads, the firing frequency of the print head or angling or rotating the print heads.

Abstract: A razor blade including a substrate with a coating joined to the substrate defining a coated blade. The coated blade including a cutting edge being defined by a blade tip having a tip radius of from 50 to 350 angstroms. The coated blade having a pair of first facets extending from the blade tip and a pair of second facets extending from the respective first facets, a facet angle from 90° to 135°, a facet width from 0.38 micrometers to 0.65 micrometers a wedge angle from 5° to 30°, and a thickness of between 0.8 and 1.5 micrometers measured at a distance of 1 micrometer from the blade tip.

Abstract: A razor cartridge, a razor blade, and a process of producing a razor cartridge and razor blade is provided including at least one blade positioned between the guard and the cap where the visible surface of the at least one razor blade includes a printed object wherein the printed object has a height dimension of from about 0.04 mm to about 0.60 mm. The printed object may extend continuously along the length of the razor blade and/or may have multiple portions having a comb-like structure. The printed object appears as a solid object to a viewer's naked eye. The solid object includes a plurality of printed ink dots not visible to the viewer's naked eye. The printed object of flexible, polymer ink may act as a guard element on the razor blade which helps with glide and to manage a user's skin (e.g., bulge) during shaving.

Abstract: A low-friction coating includes: an aliphatic hydrocarbon group showing a peak in a region of 2,900 cm?1 to 3000 cm?1 in an infrared absorption spectrum; a carbonyl group showing a peak in a region of 1,650 cm?1 to 1,800 cm?1 in an infrared absorption spectrum; an aromatic component (C7H7+) showing a peak at mass 91.1 in a positive ion spectrum obtained by TOF-SIMS; and a condensed ring based component (C9H7+) showing a peak at mass 115.2 in the positive ion spectrum obtained by TOF-SIMS.

Abstract: A low-friction coating includes: an aliphatic hydrocarbon group showing a peak in a region of 2,900 cm?1 to 3000 cm?1 in an infrared absorption spectrum; a carbonyl group showing a peak in a region of 1,650 cm?1 to 1,800 cm?1 in an infrared absorption spectrum; an aromatic component (C7H7+) showing a peak at mass 91.1 in a positive ion spectrum obtained by TOF-SIMS; and a condensed ring based component (C9H7+) showing a peak at mass 115.2 in the positive ion spectrum obtained by TOF-SIMS.

Abstract: A scribing wheel for scribing a brittle material-made substrate. A disc-shaped scribing-wheel base material in use is so designed that a mid-portion of a disc periphery has the largest diameter. A diamond film is formed on the periphery by a CVD method. The periphery is ground in the middle so that a plane including a circle defined by ridge line becomes perpendicular to the central axis of the scribing wheel.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip. The substrate has thicknesses of 1.60-1.75 micrometers and 9.25-10.00 micrometers measured at a distance of four and forty micrometers from the blade tip, respectively. A ratio of the thickness measured at four micrometers to the thickness measured at forty micrometers is between 0.165-0.185. The substrate thickness is about 2.70-3.00 micrometers at eight micrometers from the blade tip, about 4.44-5.00 micrometers at sixteen micrometers from the blade tip with a thickness ratio measured at four micrometers and eight micrometers between 0.56-0.62, and a thickness ratio measured at four micrometers and sixteen micrometers between 0.32-0.40. The blade edge shape is defined by equation w=adn where “a” is between 0.50-0.62 and “n” is between 0.76-0.80. An included angle of less than 7° is measured at a distance of forty micrometers or greater from the blade tip. A nitrided substrate may also be provided.

Abstract: A cold field emitter for emitting an electron beam for an electron beam device is described. The emitter includes an emitter tip having a tip surface; and two or more adjacent facets formed at the tip surface and having facet boundaries, each of the facets forming a recess in the emitter tip, wherein the facets are separated. An intermediate area is provided between and around the two or more adjacent facets and the intermediate area is configured for electron emission. Further, an electron beam device, a method for operating an electron beam device and a method for producing an emitter for an electron beam device is described.

Abstract: Razors cartridges including a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap are provided. A first blade defines a blade edge nearest the guard and a second blade defines a blade edge nearest the cap. The first blade has a cutter force less than the cutter force of the second blade.

Abstract: The present invention provides a method for preparing a matte anti-fingerprint stainless steel decorative plate. The method comprises the steps of: 1) selecting a polymer coating material, wherein the polymer coating material is formed by mixing a film forming material, an inorganic nano-filler, a solvent and an auxiliary agent, wherein the film forming material comprises the following ingredients based on the weight ratio: 30-50 parts of acrylate composite resin, 5-20 parts of amino resin, and 5-15 parts of epoxy resin; and 1-8 parts of a matting agent and 1-8 parts of an anti-settling agent are added; and 2) performing a spray coating using the polymer coating material, wherein a coating film has a thickness of 1.5-2.5 ?m, the precision of the atomization air pressure of a spray gun is controlled at ±0.

Abstract: A razor blade having a substrate with a cutting edge being defined by a sharpened tip. The substrate has a thickness of between about 1.3 and 1.6 micrometers measured at a distance of four micrometers from the blade tip, a thickness of between about 2.2 and 2.7 micrometers measured at a distance of eight micrometers from the blade tip, a thickness of between about 3.8 and 4.9 micrometers measured at a distance of sixteen micrometers from the blade tip, a ratio of thickness measured at four micrometers from the blade tip to the thickness measured at eight micrometers from the blade tip of at least 0.55 and a ratio of thickness measured at four micrometers from the blade tip to the thickness measured at sixteen micrometers from the blade tip of at least 0.30.

Abstract: A razor cartridge includes razor blade assemblies having an inter-blade guard attached to a side of a razor blade. The razor blade is formed from strip that is manufactured including a thermal oxidation process to form a chromium oxide layer on the side surface of the razor blade. This oxide film prevents electrochemical corrosion of the razor blade that may be visible to a user and prevents real or perceived premature failure of the razor blade and thus the razor cartridge during its extended life. The razor blade assembly may also have an array of closely spaced droplets of a liquid adapted to inhibit corrosion of the razor blade applied to the side of the razor blade visible to a user.

Abstract: Razors are described herein. In some instances the razors include a safety razor blade unit that includes a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap. A first blade defines a blade edge nearer the guard and a second blade defines a blade edge nearer the cap. The first blade has a cutter force greater than the cutter force of the second blade. In some instances the razors provide a comfortable shave having improved closeness.

Abstract: A blade assembly and razor utilizing same are provided. The blade assembly includes at least one blade and an electrode element being electrically insulated from the blade and from a skin surface contactable by the blade. The blade in combination with the electrode form hydroxyl ions near the blade edge during shaving.

Abstract: The present invention relates to a cutting tool, in particular in the form of a razor blade, a scalpel, a knife, a machine knife, scissors etc., which has a synthetic diamond layer with a cutting edge. The diamond layer thereby consists of fine-crystalline diamond.

Abstract: The invention discloses utilizing isostatic-press (IP) processes apply a polymeric material (e.g, a PTFE foil) to uncoated razor blade edges forming thin, dense, and uniform coatings on blade edges which in turn exhibit low initial cutting forces correlating with more comfortable shaves. The isostatic press may be a hot isostatic press (HIP) or a cold isostatic press (CIP) or any other isostatic press process. The HIP conditions may include an environment of elevated temperatures and pressures in an inert atmosphere. The CIP conditions may include room temperature and elevated pressure. The polymeric material may be a fluoropolymer or non-fluoropolymeric material or any composite thereof. The lower surface of the polymeric material may be modified (e.g., chemical etching) to enhance adhesion to the blade edge. Two or more layers of polymeric material of similar or different properties may be isostatically pressed onto the uncoated blades.

Abstract: The present invention generally relates to blades for utility knives, craft knives, box cutters, and other cutting tools. Specifically, this invention relates to cutting blades manufactured from ceramics.

Abstract: The invention discloses utilizing isostatic-press (IP) processes apply a polymeric material (e.g, a PTFE foil) to uncoated razor blade edges forming thin, dense, and uniform coatings on blade edges which in turn exhibit low initial cutting forces correlating with more comfortable shaves. The isostatic press may be a hot isostatic press (HIP) or a cold isostatic press (CIP) or any other isostatic press process. The HIP conditions may include an environment of elevated temperatures and pressures in an inert atmosphere. The CIP conditions may include room temperature and elevated pressure. The polymeric material may be a fluoropolymer or non-fluoropolymeric material or any composite thereof. The lower surface of the polymeric material may be modified (e.g., chemical etching) to enhance adhesion to the blade edge. Two or more layers of polymeric material of similar or different properties may be isostatically pressed onto the uncoated blades.

Abstract: The invention discloses isostatic-pressing (IP) applied to polymer (e.g., PTFE) coated razor blade edges to produce thin, dense, and uniform blade edges which in turn exhibit low initial cutting forces correlating with a more comfortable shaves. The isostatic press utilized may be a hot isostatic press (HIP) or cold isostatic press (CIP) or any other isostatic press process. The HIP conditions may include an environment of elevated temperatures and pressures in an inert atmosphere. The HIP conditions may be applied to non-sintered coatings or sintered coatings or before or after a Flutec® process is applied to coatings. CIP conditions may include room temperature and elevated pressure. The polymeric material may be a fluoropolymer or a non-fluoropolymer material or any composite thereof. It may be deposited initially by any method, including but not limited to, dipping, spin coating, sputtering, or thermal Chemical Vapor Deposition (CVD).

Abstract: In a vacuum chamber, the edge of each blade group is subjected to an ion beam treatment under predetermined conditions using a plasma ion gun and argon as a medium, and is subjected to a plasma ion implantation of nitrogen plasma under predetermined conditions using a plasma ion implantation gun. As a result, it is possible to provide a blade member having an edge of a cutting quality enhanced by increasing the sharpness, a blade member having an edge of a rigidity enhanced by increasing the hardness, and a working apparatus capable of working those edges efficiently.

Abstract: A razor cartridge includes razor blade assemblies having an inter-blade guard attached to a side of a razor blade. The razor blade is formed from strip that is manufactured including a thermal oxidation process to form a chromium oxide layer on the side surface of the razor blade. This oxide film prevents electrochemical corrosion of the razor blade that may be visible to a user and prevents real or perceived premature failure of the razor blade and thus the razor cartridge during its extended life. The razor blade assembly may also have an array of closely spaced droplets of a liquid adapted to inhibit corrosion of the razor blade applied to the side of the razor blade visible to a user.

Abstract: Cutting members for razors are provided that have a blade portion and a base portion, the blade portion having a cutting edge region terminated at a free end thereof and an opposing non-cutting edge region, the blade portion being bent relative to the base portion in a bent portion spaced from the cutting edge region and adjacent to the non-cutting edge region, wherein the bent portion extends about 108 degrees to about 115 degrees from the base portion, the bent portion having a radius of about 0.30 mm to about 0.45 mm, at least part of the cutting member having a hardness of about hardness of about 540 HV to about 750 HV, and a thickness of the bent portion is less than the average thickness of the cutting member.

Abstract: This invention relates to a novel application of hard, low friction aluminum magnesium boride (AlMgB14, also known as BAM) based ceramic coatings to surfaces of razor components and in particular to blade edges of razor blades. On razor blade edges, these coatings may elevate blade performance, while also simplifying the manufacturing process.

Abstract: A razor blade including a substrate with a coating joined to the substrate defining a coated blade. The coated blade including a cutting edge being defined by a blade tip having a tip radius of from 50 to 350 angstroms. The coated blade having a pair of first facets extending from the blade tip and a pair of second facets extending from the respective first facets, a facet angle from 90° to 135°, a facet width from 0.38 micrometers to 0.65 micrometers a wedge angle from 5° to 30°, and a thickness of between 0.8 and 1.5 micrometers measured at a distance of 1 micrometer from the blade tip.

Abstract: A razor blade including a substrate with a coating joined to the substrate defining a coated blade. The coated blade including a cutting edge being defined by a blade tip having a tip radius of from 500 to 1500 angstroms. The coated blade having a thickness of between 0.3 and 0.5 micrometers measured at a distance of 0.25 micrometers from the blade tip, a thickness of between 0.4 and 0.65 micrometers measured at a distance of 0.5 micrometers from the blade tip, a thickness of between 0.61 and 0.71 micrometers measured at a distance of 1 micrometer from the blade tip, a thickness of between 0.96 and 1.16 micrometers measured at a distance of 2 micrometers from the blade tip, and a thickness of between 1.56 and 1.91 micrometers measured at a distance of 4 micrometers from the blade tip.

Abstract: Disclosed is a razor blade having a mineral blade with a mineral cutting edge, with the mineral cutting edge having a radius of less than about 20 nanometers and an angle of about 40-50 degrees and wherein the mineral blade is coated in an adhesion promoter and an outer layer and a method of making the razor blade. Also disclosed is a razor having a mineral blade, and a method of making the razor.

Abstract: A utility knife blade comprises a cutting edge portion and a remaining portion. The remaining portion is tempered martensite and has a first hardness. The cutting edge portion comprises a region that has been locally re-heat treated so that the microstructure in the cutting edge portion is untempered martensite having a hardness greater than the first hardness.

Abstract: A utility blade for use with conventional retractable and fixed blade utility knives comprising a blade body having a generally trapezoidal configuration defined by a cutting edge, an opposite back edge, a pair of opposing side edges and a pair of cutting points defined by the points of intersection between the side edges and the cutting edge. The blade further defines a pair of score lines, each proximate to one of the side edges. The score lines enable the user to remove a dulled or damaged cutting point, which in turn provides the user with two additional cutting points defined by the points of intersection between the score lines and the cutting edge. Further, the blade is configured with one or more notches strategically located on the back edge of the blade, such that each cutting point can extend from the utility knife at approximately the same distance.

Abstract: The present invention relates to a process for forming a razor blade. The process includes the steps of: a) providing a substrate, b) forming a wedge-shaped sharpened edge on the substrate that has an included angle of less than thirty degrees and a tip radius of less than 1,000 angstroms, c) placing the substrate in a vacuum chamber, d) placing a first solid target in the vacuum chamber, e) providing a gas to be ionized in the vacuum chamber, and f) generating ions from the first solid target by applying a negative voltage to the first solid target in pulses, the ions forming a thin film coating on the wedge-shaped sharpened edge on the substrate.

Abstract: A utility blade for use with conventional retractable and fixed blade utility knives comprising a blade body having a generally trapezoidal configuration defined by a cutting edge, an opposite back edge, a pair of opposing side edges and a pair of cutting points defined by the points of intersection between the side edges and the cutting edge. The blade further defines a pair of score lines, each proximate to one of the side edges. The score lines enable the user to remove a dulled or damaged cutting point, which in turn provides the user with two additional cutting points defined by the points of intersection between the score lines and the cutting edge. Further, the blade is configured with one or more notches strategically located on the back edge of the blade, such that each cutting point can extend from the utility knife at approximately the same distance.

Abstract: A system for sharpening and or honing a multi-bladed razor cartridge including a handle and flexible honing material. The flexible honing material is used to hone the razor blades prior to use and to remove excess moisture from the razor blades once the razor blades are cleaned after shaving. The flexible honing material is made of a chamois which can conform to the shape of the razor blade cartridge and razor blades within the cartridge.

Abstract: The present disclosure is generally directed to a personal grooming product or device (e.g., foil shaver, rotary shaver, etc.) having a metal coating on one or more surfaces thereof, the grooming product being designed for contacting the skin (e.g., the human hand or face, or the skin of an animal, such as during the act of pet grooming). More specifically, the present disclosure is directed to a personal grooming product or device having a layer of some measurable thickness on such a surface, wherein the layer comprises or contains a tarnish resistant, hypoallergenic and/or antimicrobial silver-containing alloy.

Abstract: Disclosed is a razor or cutting blade of a thin sheet-like construction having a ceramic material contained therein. The blade is either wholly made of a ceramic material or has a coating of ceramic material thereon. The blade may be made of many different shapes, such as a rectangle a trapezoid. The blade may have a metal ridge on one edge of the rectangle while the other longitudinal edge is sharpened. The trapezoid construction may have the long edge sharpened in addition to one of the slanted edges. Any of the blades may have notches in non-sharpened edges thereof to act as locating guides when placed in a manipulating handle.

Abstract: Razors are described herein. In some instances the razors include a safety razor blade unit comprising a guard, a cap, and at least two blades with parallel sharpened edges located between the guard and cap. A first blade defines a blade edge nearer the guard and a second blade defines a blade edge nearer the cap. The first blade has a cutter force greater than the cutter force of the second blade. In some instances the razors provide a comfortable shave having improved closeness.

Abstract: A razor blade including a substrate with a cutting edge, the substrate includes a mixed nitride-substrate interregion disposed at or beneath a surface of the substrate, the mixed nitride-substrate interregion being substantially free of a compound layer.

Abstract: A disposable safety razor includes a blade housing and a blade disposed within the blade housing to expose a cutting edge suitable for shaving. The blade housing and the blade have complementary characteristics which result in destruction of the blade upon an attempt to remove the blade from within the blade housing. In this regard, the blade housing comprises a substantially rigid housing and the blade comprises a brittle ceramic blade. The safety razor further includes a handle attached to the blade housing. The handle is made from a pliable plastic material that forms an enclosure filled with a dispensable liquid.

Abstract: A composite utility blade and method of making such a blade involves butt joining a high speed or tool steel wire to a front edge of an alloy steel backing strip. The wire defines a predetermined cross-sectional shape that substantially corresponds to the cross-sectional shape of the cutting edge of the blade. The wire is electron beam welded to the backing strip to form a composite strip defining a first metal portion formed by the alloy steel backing strip, a second metal portion formed by the high speed or tool steel wire, and a weld region joining the first and second metal portions. The composite strip is then annealed, and the annealed strip is straightened to eliminate any camber therein. The annealed composite strip is then hardened such that the first metal portion defines a first surface hardness and the second metal portion defines a second surface hardness greater than the first surface hardness.

Abstract: The invention relates to a method for forming a thin, high hardness coating and devices comprising it. The method of the invention consists in depositing, by magnetron cathode sputtering, a titanium film on at least one surface of a substrate under a partial pressure of argon of 1 Pa, then in depositing, by magnetron cathode sputtering, a titanium nitride film, onto the film obtained by introducing nitrogen into the cathodic sputtering chamber while maintaining a partial pressure of 1 Pa, and in depositing a film of a composite nanostructured material based on titanium, zirconium, boron and nitrogen onto the film obtained by magnetron cathode sputtering in active co-sputtering mode. The method of the invention can be applied in many fields, and in particular in the mechanical field in order to improve the surface hardness of mechanical components.

Abstract: A method of manufacturing a blade including heating and quenching a coil of strip steel material to harden the material, heating the strip steel material to temper the material, grinding a first angle along an edge of the material, and subsequent to the grinding, re-hardening, for example by induction heating, the edge of the material.

Abstract: Razor blades and other shaving implements are disclosed that include a blade substrate having first and second major surfaces and first and second edges of which at least one edge is configured as a cutting edge. At least one of the major surfaces includes a region that includes at least one polymer carrying at least one bioactive agent in a manner such that use of the blade for shaving an area of skin causes release of the bioactive agent onto the area of skin. The bioactive agent can be, e.g., at least one skin-medicament and/or at least one skin-care agent, or mixtures thereof. The bioactive agent is released in real time, relative to shaving, onto the skin so as to exert its effect as soon as possible on the skin area.

Abstract: A razor blade is provided, which achieves improved safety in use and reduced cutting resistance to an object to be cut such as beard and hair, as compared with conventional razor blades. This razor blade can be obtained by using, as a silicon thin sheet, a single crystal silicon material such as Si wafer or a polycrystalline silicon material including relatively large silicon crystal grains, forming at least one opening in the silicon thin sheet by chemical etching, and forming a cutting edge made of silicon single crystal by ion beam etching without machining such that the cutting edge projects into the opening and has a nose radius of 0.5 ?m or less, and preferably 0.1 ?m or less.

Abstract: An apparatus and method for a cutting blade having a pointed tip and ultra-flat faces that intersect at ultra-sharp edges. The cutting blade is batch-fabricated on a standard {100} semiconductor mono-crystalline silicon wafer using conventional anisotropic wet etching silicon micromachining techniques as a pair of spaced-apart substantially parallel and planar top and bottom surfaces each formed in {100} planes of a {100} mono-crystalline silicon substrate with first and second mutually rotated cutting edges formed between the top and bottom surfaces of the substrate and substantially parallel thereto in adjacent {111} planes that form a first pointed tip at an intersection therebetween, and having third and fourth cutting edges formed between the top and bottom surfaces of the substrate and substantially parallel thereto in adjacent {110} planes with the third and fourth cutting edges forming different pointed intersections with the first and second mutually rotated cutting edges.

Abstract: A blade with improved sharpness and durability is disclosed. The blade includes a base plate having an edge and a coating layer for coating the edge. The coating layer is formed of a material handling metal, and a tip of the coating layer is sharpened. It is preferred that an angle (Ba) between two tapered surfaces be between 15 to 45 degrees.