Skiving or scarfing is the process of cutting material off in slices, usually

metal A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated wit ...

, but also

leather Leather is a strong, flexible and durable material obtained from the tanning (leather), tanning, or chemical treatment, of animal skins and hides to prevent decay. The most common leathers come from cattle, sheep, goats, equine animals, buffal ...

or laminates. Skiving can be used instead of

rolling Rolling is a Motion (physics)#Types of motion, type of motion that combines rotation (commonly, of an Axial symmetry, axially symmetric object) and Translation (geometry), translation of that object with respect to a surface (either one or the ot ...

the material to shape when the material must not be work hardened, or must not shed minute slivers of metal later which is common in

cold rolling In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness, to make the thickness uniform, and/or to impart a desired mechanical property. The concept is simi ...

processes. It can also be used to create fins on a block of metal, not shaving the part entirely off. In metalworking, skiving can be used to remove a thin dimension of material or to create thin slices in an existing material, such as

heat sinks A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is thermal management (electronics), ...

where a large amount of surface area is required relative to the volume of the piece of metal. The process involves moving the material past precision-profiled tools made to an exact shape, or past plain

cutting tool Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for cutting are the knife and saw, or in medicine and science the scalpel an ...

s. The tools are typically made of

tungsten carbide Tungsten carbide (chemical formula: ) is a carbide containing equal parts of tungsten and carbon atoms. In its most basic form, tungsten carbide is a fine gray powder, but it can be pressed and formed into shapes through sintering for use in in ...

-based compounds. It requires a minimum material feed rate to cut successfully. At speeds below those of metal planing or about 10 meters/minute (33 feet/minute), the skiving tools can be vibrated at high frequency to increase the relative speed between the tool and workpiece. In early machines, it was necessary to precisely position the strip relative to the cutting tools, but newer machines use a floating suspension technology which enables tools to locate by material contact. This allows mutual initial positioning differences up to approximately followed by resilient automatic engagement. Products using this technology directly are automotive seatbelt springs, large

power transformer Power may refer to: Common meanings * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power, a type of energy * Power (social and political), the ability to influence people or events Ma ...

winding strips,

rotogravure Rotogravure (or gravure for short) is a type of intaglio printing process, which involves engraving the image onto an image carrier. In gravure printing, the image is engraved onto a cylinder because, like offset printing and flexography, it u ...

plates, cable and

hose clamp A hose clamp is a device used to attach and seal a hose (tubing), hose onto a fitting such as a barb (hose), barb or nipple (plumbing), nipple. Materials The core range of hose clamps on the open market are made from materials like stainles ...

s, gas tank straps, and window counterbalance springs. Products using the process indirectly are tubes and pipes where the edge of the strip is accurately beveled prior to being folded into tubular form and seam welded. The beveled edges enable pinhole free welds. Another metal skiving application is for

hydraulic cylinder A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment ( engineering vehicles ...

s, where a round and smooth

cylinder bore In a piston engine, the bore (or cylinder bore) is the diameter of each cylinder. Engine displacement is calculated based on bore, stroke length and the number of cylinders: displacement = The stroke ratio, determined by dividing the bore b ...

is required for proper actuation. Several skiving knives on a round tool pass through a bore to create a perfectly round hole. Often, a second operation of

roller burnishing Roller may refer to: Birds *Roller, a bird of the family Coraciidae * Roller (pigeon), a domesticated breed or variety of pigeon Devices * Roller, an element of a rolling-element bearing * Roller, used in rolling (metalworking) * Roller, i ...

follows to cold-work the surface to a mirror finish. This process is common among manufacturers of hydraulic and pneumatic cylinders. Compared to honing, skiving and roller burnishing is faster. Skiving can be applied to gear cutting, where internal gears are skived with a rotary cutter (rather than shaped or broached) in a process analogous to the hobbing of external gears.

Heat sinks

Skiving is also used for the manufacturing of

heat sink A heat sink (also commonly spelled heatsink) is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant, where it is thermal management (electronics), ...

s for PC cooling products. A PC cooler created by skiving has the benefit that the heat sink base and fins are created from a single piece of material (copper or aluminum), providing improved heat dissipation and heat transfer from base to fins. Additionally, the skiving process also increases the roughness of the fins. Unlike the underside of a heat sink, which needs to be smooth for maximum contact area with the heat source, the fins benefit from this roughness because it increases the fins' surface area on which to dissipate heat into the air. The fins may be made much thinner and closer together than by

extrusion Extrusion is a process used to create objects of a fixed cross section (geometry), cross-sectional profile by pushing material through a Die (manufacturing), die of the desired cross-section. Its two main advantages over other manufacturing pro ...

or formed sheet processes, which can offer greater heat transfer in high-performance waterblocks for

water cooling file:KKP Auslauf.jpg, Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water i ...

References

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External links

Skiving machine patentThe little-known life of the scarfing tool
Machine tools Metalworking

Heat sinks

See also

References

External links