Glossary for Seals, Gaskets, O-Rings, Orings, Rubber.

Includes the terms and definitions for seals, seal, orings, gasket, gaskets, hydraulic seals, hydraulic seal, metric seals, metric seal, o-rings, o-ring, viton, teflon, silicone, rubber, nitrile, ucup, plastic, metric orings, injection molding, oil seals, packings, parts, molding, machining.

This is perhaps the most comprehensive glossary of seal, gasket, packing and molded rubber parts terms available on the internet.

Simply click any letter below to search through the glossary.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

For more information visit:


Abrasion - Surface loss of a material due to frictional forces.

Abrasion - The wearing away of a materiel surface by friction. Particles become detached by a combined cutting, shearing and tearing action. Furnace carbon blacks are the best ingredients found for increasing the resistance of rubber compounds to abrasion.

Abrasion resistance - The resistance of a material to loss of surface particles due to friction.

Accelerated aging - A method in which an attempt is made to produce and measure the effects of natural aging in a shorter period.

Accelerator (of vulcanization) - Any substance, which hastens the vulcanization of rubber causing it to take place in shorter time or at a lower temperature. In earlier days basic oxides such as limes, litharge and magnesia were recognized as having this function. Nowadays the important accelerators are organic substances containing either nitrogen or sulfur or both. According to potency, or speed of action, accelerators are sometimes classified as slow, medium, rapid, semi-ultra and ultra-accelerators. Most accelerators enhance tensile properties, and many improve age resistance.

Accelerator Ultra - An accelerator which causes very rapid vulcanization, even at comparatively low temperatures. Tetramethylthiuram disulfide is a typical ultra-accelerator. The dislkyldithiocarbamates and xanthates are also ultra-accelerators.

Acid Resistant - Withstands the action of acids.

Acrylonitrile - Cyanoethylene, vinyl cyanide, CH2=CHCN a volatile liquid boiling at 178.50 C, prepared by dehydration of ethylene cyanhydrin and by catalytic addition or hydrogen cyanide to acetylene. Used in co-polymerization with butadiene in the manufacture of Buna N or Nitrile rubbers.

Activator - A substance, which by chemical interaction promotes a specific chemical action of a second substance. Most accelerators require activators to bring out their full effect in vulcanization, e.g., zinc oxide or other metallic oxides; some accelerators require a fat acid, especially with zinc oxide.

Adapters - A "V" shaped ring either male or female to fit together with "V" shaped rings to form a set of adjustable hydraulic packing.

Adhesion - The state in which two surfaces are held together by interfacial forces which may consist of molecular forces or interlocking action, or both.

Adhesion - The clinging or sticking of two (2) material surfaces to one another. In rubber parlance, the strength of bond or union between two (2) rubber surfaces or plies cured or uncured. The bond between a cured rubber surface and a nonrubber surface, e.g., glass, metal, wood, fabric.

Adhesion Failure - The separation of two materials at the surface interface rather than within one of the materials itself.

Aging - (1) The irreversible change of material properties after environ- mental exposure for an interval of time; (2) Exposing materials to an environment for an interval of time.

Aging - A progressive change in the chemical and physical properties or rubber, especially vulcanized rubber, usually marked by deterioration. Aging may be retarded by the use or antioxidants.

Air Checks - See Air trap below

Air trap - Surface markings or depressions due to trapping air voids in body or part due to entrapped gas between the materials being cured and the mold or press surface.

Air Curing - The vulcanization of a rubber product in air as distinguished from vulcanizing in a press or steam vulcanizer.

Aluminum Seal Rings - Sealing rings for pistons made from high grade aluminum alloy

Amines - Derivatives of ammonia in which one or more or (lie hydrogen atoms is replaced by an alkyl or aryl radical. They are called primary, secondary and tertiary amines according to the number of such substitutions. Example: RNH2, R2NH, AND R3N.

Aniline Point - The temperature in degrees Fahrenheit at which a kerosene, diesel fuel or distillate is miscible with an equal volume of aniline. Low aniline point hydrocarbons tend to swell rubbers to a greater degree than those with a high aniline point.

Anti-Extrusion Rings - Also, called back-up rings or anti-extrusion rings. Used to fit behind rubber o-ring seals to prevent extrusion into the gap between the metal pieces

Antioxidant - Usually organic and nitrogenous. A substance, which inhibits or retards oxidation and certain other kinds of aging. Some antioxidants cause staining or discoloration of the rubber compound on exposure to light and are used only in black or dark-colored goods. Others (phenolic), described as non-staining, are used in white or light-colored goods.

Anti-vibration Mounts - Rubber molded pieces used as padding between a motor and the frame to prevent vibration transfer to the machine to which it is mounted.

Apportionment - Referred to here as a part of Reliability Engineering. Synonymous with the term Reliability Apportionment, which is the assign- ment of reliability goals from system to subsystem in such a way that the whole system will have the required reliability.

AQ Seal - A special purpose hydraulic seal

Assortment Kits - Aconvenient package containing several sizes of the same seal, o-ring or retainer ring.

Autoclave - A pressure vessel into which materials or articles can be placed and exposed to steam under pressure. It is commonly used for vulcanization.

Automatic U-joints - Also called u-cups, ucups or u cups. A "U" shaped sealing ring made from a strong pliable plastic or rubber.

For more information visit:

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z


© 2003-2004 All rights reserved.