Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: A cutting element comprises a cutting table of a polycrystalline hard material including a cutting face, a sidewall, and at least one peripheral cutting edge portion between the cutting face and the sidewall. A radius of curvature of the peripheral cutting edge portion is greater than a radius of curvature of at least another peripheral edge portion between the cutting face and the sidewall. An earth-boring tool may include one or more such cutting elements.

Abstract: A cutting element configured to mitigate spalling on a front cutting face thereof. The cutting element include a diamond table having the front cutting face defined thereon and at least one recess defined on the front cutting face of the diamond table. The at least one recess has a width within a range of 25.0 ?m to 650 ?m and a depth within a range of 25.0 ?m to 600 ?m. Methods of forming a cutting element configured to mitigate spalling on the front cutting face thereof. The methods including forming at least one recess on a front cutting face of a diamond table to have a width within a range of 25.0 ?m to 650 ?m and a depth within a range of 25.0 ?m to 600 ?m. Method of using a cutting element configured to mitigate spalling on the front cutting face thereof.

Abstract: A cutting element for an earth-boring tool includes a substrate and volume of superabrasive material positioned on the substrate. The volume of superabrasive material includes a cutting face having at least one recess extending into the volume of superabrasive material and/or at least one protrusion extending outward from the volume of superabrasive material. The volume of superabrasive material includes a first chamfer surface having a peripheral edge and a radially innermost edge. The peripheral edge of the first chamfer surface is located proximate a cutting edge of the volume of superabrasive material. A radial width of the first chamfer surface is between about 0.002 inch and about 0.045 inch. The volume of superabrasive material also includes a second chamfer surface having a peripheral edge and a radially innermost edge. The peripheral edge of the second chamfer surface is located adjacent the radially innermost edge of the first chamfer surface.

Abstract: Methods of evaluating prototype cutting elements for earth-boring tools may involve generating first and second sets of virtual representations of cutting elements from first and second sets of used cutting elements. First and second sets of measures of damage corresponding to damage for each of the first and second sets set of virtual representations of cutting elements may be determined. A best-performing set of cutting elements from the first and second sets of used cutting elements according to the first and second sets of measures of damage may be identified by performing a statistical analysis.

Abstract: Methods of forming an earth-boring tool may involve attaching one or more cutting elements to a replaceable cutting structure and positioning the replaceable cutting structure proximate a region of a body of an earth-boring tool that is susceptible to at least one of localized wear and localized impact damage. The replaceable cutting structure may be secured to the body. Methods of repairing an earth-boring tool may involve bringing a replaceable cutting structure proximate at least one portion of a body of an earth-boring tool exhibiting at least one of localized wear and localized impact damage. The replaceable cutting structure may be attached to the earth-boring tool at the at least one portion.

Abstract: Methods of forming an earth-boring tool may involve attaching one or more cutting elements to a replaceable cutting structure and positioning the replaceable cutting structure proximate a region of a body of an earth-boring tool that is susceptible to at least one of localized wear and localized impact damage. The replaceable cutting structure may be to the body. Methods of repairing an earth-boring tool may involve bringing a replaceable cutting structure proximate at least one portion of a body of an earth-boring tool exhibiting at least one of localized wear and localized impact damage. The replaceable cutting structure may be attached to the earth-boring tool at the at least one portion.

Abstract: A cutting element for an earth-boring tool includes a volume of superabrasive material having a cutting face and a shaped feature on the cutting face. The shaped feature may include at least one of a recess extending into the volume of superabrasive material from the cutting face and a protrusion extending outward from the cutting face. A first portion of the cutting face may have a first surface roughness, and a second portion of the cutting face may have a second surface roughness greater than the first surface roughness of the first portion of the cutting face. The volume of superabrasive material may be disposed on a substrate. Methods of forming cutting elements may include forming one or more shaped features in a cutting face of the cutting elements. Earth-boring tools may include such cutting elements.

Abstract: Earth-boring tools may comprise rotatable cutting elements rotatably connected to protruding journals, which may be at least partially located within inner bores extending through the rotatable cutting elements. A rotationally leading end of one of the protruding journals may not extend beyond a cutting face of its associated rotatable cutting element. Alternatively, a protruding journal may comprise a chip breaker protruding from a cutting face of a rotatable cutting element. Methods of removing an earth formation may include directing cuttings forward, away from a cutting face of a rotatable cutting element when the cuttings reach an inner bore of the rotatable cutting element, and rotating the rotatable cutting element around a protruding journal at least partially located in the inner bore.

Abstract: Downhole tools with a topographical pattern, and anti-balling material over the topographical pattern. The topographical pattern may be defined by at least one of a plurality of recesses extending into a surface of a body of the tool and a plurality of protrusions protruding from the surface. Downhole tools include an insert disposed within a recess in a body, and the insert comprises an anti-balling material having a composition selected to reduce accumulation of formation cuttings on the tools when the tools are used to form or service a wellbore. Downhole tools include anti-balling material disposed over a porous mass provided over the surfaces of the tools. Methods of forming downhole tools include providing anti-balling material over features on and/or in a surface of a body of a tool. Methods of repairing downhole tools include removing an insert therefrom and disposing a replacement insert therein.

Abstract: Cutting elements for an earth-boring tool include a substrate base and a cutting tip. The cutting tip may include a first generally conical surface, a second, opposite generally conical surface, a first flank surface extending between the first and second generally conical surfaces, and a second, opposite flank surface. The cutting tip may include a central axis that is not co-linear with a longitudinal axis of the substrate base. The cutting tip may include a surface defining a longitudinal end thereof that is relatively more narrow in a central region thereof than in a radially outer region thereof. Earth-boring tools include a body and a plurality of such cutting elements attached thereto, at least one cutting element oriented to initially engage a formation with the first or second generally conical surface thereof. Methods of drilling a formation use such cutting elements and earth-boring tools.

Abstract: A method of forming a casing bit includes positioning a cutting element adjacent an outer surface of a casing bit body. The cutting element has a superhard material and a bonding material that is used to bond the cutting element to a body of the casing bit. The bonding material may be a weldable or brazable metal alloy, and a welding process or a brazing process, respectively, may be used to bond the cutting elements to body of the casing bit. Casing bits fabricated using such methods may exhibit reduced bond strength between the cutting elements and the casing bit body.

Abstract: Methods of attaching a polycrystalline diamond compact (PDC) element to a substrate include maintaining a gap between the PDC element and an adjacent substrate, and at least substantially filling the gap with a deposition process. Methods of forming a cutting element for an earth-boring tool include forming a PDC element by pressing diamond crystals together, forming a substrate including a particulate carbide material and a matrix material, leaving a gap between at least portions of the PDC element and the substrate, masking surfaces of the PDC element and of the substrate that do not face the gap, and forming an adhesion material on surfaces of the PDC element and of the substrate that face the gap. Cutting elements for earth-boring tools include a PDC element attached to a substrate with at least one of diamond, diamond-like carbon, a carbide material, a nitride material, and a cubic boron nitride material.

Abstract: A cutting element for use in a drill bit for drilling subterranean formations includes a cutting body having a substrate, and a superabrasive layer overlying an upper surface of the substrate. The cutting element further includes a sleeve including another superabrasive layer and surrounding the peripheral side surface of the cutting body.

Abstract: Earth-boring tools may comprise rotatable cutting elements rotatably connected to protruding journals, which may be at least partially located within inner bores extending through the rotatable cutting elements. A rotationally leading end of one of the protruding journals may not extend beyond a cutting face of its associated rotatable cutting element. Alternatively, a protruding journal may comprise a chip breaker protruding from a cutting face of a rotatable cutting element. Methods of removing an earth formation may include directing cuttings forward, away from a cutting face of a rotatable cutting element when the cuttings reach an inner bore of the rotatable cutting element, and rotating the rotatable cutting element around a protruding journal at least partially located in the inner bore.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: Earth-boring tools may comprise rotatable cutting elements rotatably connected to protruding journals, which may be at least partially located within inner bores extending through the rotatable cutting elements. A rotationally leading end of one of the protruding journals may not extend beyond a cutting face of its associated rotatable cutting element. Alternatively, a protruding journal may comprise a chip breaker protruding from a cutting face of a rotatable cutting element. Methods of removing an earth formation may include directing cuttings forward, away from a cutting face of a rotatable cutting element when the cuttings reach an inner bore of the rotatable cutting element, and rotating the rotatable cutting element around a protruding journal at least partially located in the inner bore.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: A cutting element for an earth-boring tool includes a substrate and volume of superabrasive material positioned on the substrate. The volume of superabrasive material includes a cutting face having at least one recess extending into the volume of superabrasive material and/or at least one protrusion extending outward from the volume of superabrasive material. The volume of superabrasive material includes a first chamfer surface having a peripheral edge and a radially innermost edge. The peripheral edge of the first chamfer surface is located proximate a cutting edge of the volume of superabrasive material. A radial width of the first chamfer surface is between about 0.002 inch and about 0.045 inch. The volume of superabrasive material also includes a second chamfer surface having a peripheral edge and a radially innermost edge. The peripheral edge of the second chamfer surface is located adjacent the radially innermost edge of the first chamfer surface.

Abstract: A cutting element comprises a cutting table of a polycrystalline hard material including a cutting face, a sidewall, and at least one peripheral cutting edge portion between the cutting face and the sidewall. A radius of curvature of the peripheral cutting edge portion is greater than a radius of curvature of at least another peripheral edge portion between the cutting face and the sidewall. An earth-boring tool may include one or more such cutting elements.