Glossary of Finishing Terminology

Abrasive

A material or tool consisting of hard particles used to wear down, rub away, or machine material. Abrasive materials are often used in finishing operations.

Abrasive Blasting

A process for cleaning or finishing by a means of an abrasive directed at the work piece at differing pressures & velocities. Grits available range from extremely fine (plastic media) to very course (aluminum oxide).

Alloy

A substance that is made by combining two or more elements, one of which is typically metal.

Anodizing

A coating method that uses electricity to build an oxide layer on a ferrous or aluminum work piece. In anodizing, the work piece is the anode. This process serves two functions: aesthetics and protection from scratching and erosion.

Barrel Finishing

A mass finishing process that finishes parts inside a slowly rotating container filled with a solution and finishing media. Also called tumbling or harperizing.

Burnishing

The smoothing of surfaces by rubbing, accomplished chiefly by the movement rather than the removal of the surface layer.

Burr

A sharp, unwanted projection on a machined work piece. Burrs are removed during finishing to increase the functionality and appearance of the part.

Centrifugal Barrel Finishing (CBF)

A high-energy isotropic surface finishing process which utilizes centrifugal force, tumbling media and surfactant in specialized barrel finishing equipment. Processing can be completed wet or dry depending upon level of surface finishing required.

Chemical Polishing

The improvement in the smoothness of a metal by simple immersion in a suitable solution.

Computer Numeric Control (CNC) Machining

A control system where numerical values corresponding to desired tool or control positions are generated by a computer. Data is “dialed in” rather than controlled by cams and gears providing precise repeatable machine movements that can be programmed for optimal speeds, feeds and machine cycles.

Coating

A protective or decorative film applied to the surface of an object. Common coatings include nitride, powder coating, and thin-films, such as DLC.

Cold Working

The shaping of metal at temperatures much lower than the metal’s molten state, often at room temperature. Cold working adds certain properties to the metal, such as increased strength and improved surface finish.

Corrosion

Corrosion is the deterioration of metal and can be caused by a variety of reasons such as O2 and H20.

Deburring

A finishing process that removes burrs from a work piece.

Deflashing

The process of removing residual flashing or gates created during production processes such molding or casting.

DESCALING

The process of removing scale or oxidation from metal following thermal treatments, such as heat treating.

Diffusion Coating

An alloy coating produced by applying heat to one or more coatings deposited on a basis metal.

DLC Coating

A type of thin film coating with diamond-like properties.

Electroplating

A coating method that uses electricity and a conductive solution to deposit a layer of plating metal on a metal or nonmetal work piece. During electroplating, the work piece is the cathode.

Electropolishing

The type of surface finishing used for metal which involves submerging a work piece in a solution and using electricity. Can be used for medical equipment, aerospace part and industrial part cleaning.

Finishing Services

The processes used to refine or roughen a surface to meet surface finish requirements or to clean, strengthen or prepare the surface for additional processing. Finishing processes include cleaning, final sizing, polishing, and applying coatings.

Flashing

Small bits of residual aluminum, titanium, or stainless material on a work piece.

Flaw

Random irregularities on a surface, which can include cracks, corrosion, inclusions or scratches.

Form

The general shape of a surface.

Grinding

Grinding is an abrasive machining process that uses a grinding wheel or grinder as the cutting tool. It is used to finish work pieces that must show high surface quality and high accuracy of shape and dimension.

Hardcoat

A type of anodizing process which creates a durable surface finish on the metal.

Immersion Leak Testing

A leak test method where an object is immersed in a fluid and leak is indicated by the escape of air in the form of bubbles.

ISOTROPIC

Having uniform properties in all directions.

Lapping

A final finishing process that uses a fine abrasive to grind away small amounts of material from a work piece.

Lay

The most prominent direction of a pattern on a product’s surface.

Mass Finishing

The process of mechanical surface finishing in which multiple parts are processed simultaneously, usually in barrel or vibratory finishing equipment.

Media Blasting

A cleaning process involving the blasting of metal surfaces with abrasives to remove dirt and grease.

Passivation

The process of removing ferrous elements and free iron from stainless steel surfaces using an acid bath. A passive oxide layer forms on the surface which improves corrosion resistance.

Pickle

An acid solution used to remove oxides or other compounds from the surface of a metal by chemical or electrochemical action.

Pickling

The process of removing oxides and other compounds from a metal surface by means of an acid solution by chemical or electrochemical action.

POLISHING

The process of refining surface roughness, which can be done through a variety of processes such as by hand, chemical or mechanical (such as CBF) means. Polishing can be either shiny or matte depending upon a product’s purpose.

PROCESS ENGINEERING

The service of process design, engineering, and operation of surface finishing parameters, equipment, tumbling media and support for manufacturers wanting a turn-key in-house surface finishing solution.

RA

The mean arithmetical value of the roughness profile is defined on the sampling length and represented using a single numeric parameter.

Radiusing

A type of deburring which removes and refines the sharp edges formed on a product during the manufacturing process.

Shot

The round finishing media used in shot peening, which is commonly steel, glass or ceramic.

Shot Peening

A finishing method that uses a propelled stream of round shot beads to cold work metal surfaces. Shot peening corrects minor surface defects and strengthens the material.

Super Alloy

A substance that is made by combining two or more elements, one of which is typically metal and has the ability to operate at a high fraction of its melting point. Often used in jet turbine engines.

Surface Roughness

A component of surface texture, roughness are the shortest wavelength deviations on a surface seen as peaks and valleys, generally resulting from production process and material condition. Surface roughness can also be referred to as tooling marks.

Surface Texture

The variations in surface form which includes roughness, waviness, lay, and flaws.

Surface Waviness

A component of surface texture, waviness is the longest wavelength irregularities on a surface seen as the peaks and valleys on each end of surface roughness.. Waviness is often caused by deflection and chatter.

Tumbling

Also called barrel finishing, tumbling is a mass finishing process that finishes parts inside a rotating container containing finishing media, surfactant and often water. While the process may be done wet or dry.

Tumbling Media

Tumbling media is a material combined with abrasives and formed into different shapes and sizes used in finishing operations. Media can be made from non-organic materials such as ceramic, porcelain, resin bonded plastic, metallics, as well as organic materials like corn cob grit, wood pegs and sand.

Ultrasonic Cleaning

The process of removing contaminants from parts using high frequency sound waves and may or may not use a specialized solvent to aid in cleaning.

Vibratory Finishing

A mass finishing process that slowly finishes parts by rotating them inside a vibrating container filled with a solution and finishing media.

Vibratory Polisher

Vibratory bowl finishers operate by placing a mixture of your parts together with polishing media in a bowl-shaped machine that uses vibration to agitate the parts and media. At the end of the cycle, the parts travel up a ramp to discharge the parts and recapture the polishing media for the next batch of parts.