Knowledge Base Glossary
Glossary is usually defined as an alphabetical list of technical terms in some specialized field of knowledge. This knowledge base glossary provides a collection of knowledge base documents that define many technical terms. These terms are arranged alphabetically, but you can quickly jump to a specific term by selecting its first letter from the index of the knowledge base glossary below.
44 Glossary Terms Found
SAE
Abbreviation for: Society of Automotive Engineers
SCALLOPING
Uneven localized wear resulting from excessive endplay.
Scoop Trim
A trimmed surface which is concave.
Scoring
Gouges on the surface of a shaft, stem, or bore due to mechanical wear.
SCR
Abbreviation for: Silicon Controlled Rectifier
Scuffing
Abnormal wear due to localized welding and fracture. It can be prevented through the use of anti-wear, extreme-pressure and friction-modifier additives.
Seal
Any device designed to prevent or control the movement of fluid from one chamber to another to exclude contaminants.
Seal Assembly
A group of parts, which includes sealing surfaces, provisions for initial loading, and a secondary sealing mechanism which accommodates the radial movement necessary for installation and operation.
Seal Case
A rigid member to which the seal lip is attached
Seal Gasket
A gasket that is placed between two adjacent metal parts to make a gas tight connection.
Seal Outer Diameter
The external diameter of a lip-seal assembly, which normally corresponds to the outer diameter of the outer seal case.
Shaft Eccentricity
The radial distance which the geometric center of a shaft is displaced from the axis of shaft rotation.
Shaft Fit
Amount of interference or clearance between bearing inside diameter and shaft bearing seat outside diameter.
Shaft Hardness
The resistance to indentation. At minimum, it should be Rockwell C45.
Shaft Lead
Spiral grooves on a shaft surface caused by relative axial movement of grinding wheel to shaft.
Shaft Lobing
Uniform radial deviation of the shaft surface. An oval shaft is said to have two lobes. Faulty centerless grinding usually causes an odd number of lobes to occur. Higher order lobing is also referred to as chatter.
Shaft Out-of-Round
The deviation of the shaft cross section from a true click. Out-of-round is measured as the radial distance, on a polar chart recording, between concentric, circumscribed and inscribed circles that contain the trace and are centered to minimize the radial distance.
Shaft Surface Texture
A term used to describe the quality, appearance, or characteristics of the shaft surface resulting from operations, such as grinding, polishing, burnishing, etc.
Shaft Tolerance
This is the allowable variation in the shaft diameter.
Sheaves
Metal products with “V” shaped grooves specially designed for various types of V-belts.
Size, Actual
Actual dimensions of the part, including tolerance limits.
Size, Nominal
Approximate size of part in fractional dimensions.
Slab
A thick sheet.
Slurry
A fluid mixed with solid particles.
Spalling
Metal flaking (off) of the race or roller caused by inclusions in bearing steel, misalignment, deflection or heavy loading.
Specific Gravity
The ratio of the weight of a given substance to the weight of an equal volume of water at a specified temperature.
Spindle
A short tapered axle that supports a free rolling wheel. Also referred to as a stub axle.
Spindle Nut
A nut threaded on the end of the spindle for adjusting the wheel bearing endplay or preload.
Splices
Procedure for making endless boot or bellows from open-ended material. Splicing may be accomplished by one or more of the following: cementing, bonding, heat sealing, stitching, vulcanizing, or mechanical fasteners.
Splines
External or internal slots or grooves cut in a shaft/gear/hub or yoke used so that two different components must rotate together.
Spring Rate
The force in pounds required to deflect an expansion joint one inch in compression and elongation or in a lateral direction.
Sprockets
Metal products for high-torque synchronous power transmission systems. Sprockets are specifically designed to transmit power with only the corresponding belt product line.
Stockout
An event that causes inventory to be exhausted.
Straight Housing
A housing that is through bored. The machining passes all the way through the housing forming a through hole.
Straight Mineral Oil
A petroleum oil not containing compounds, animal or vegetable oils or chemical additives.
Strain
The unit change, due to force (stress), in the size or shape of a body compared to its original size or shapeit is non-dimensional quantity, but is frequently expressed in inches per inch, centimeters per centimeter, etc.
Stress
The intensity at a point in a body of the internal forces or components of force that act on a given plane through the point (Lbs./sq. inch).
Stroke
Maximum amount of travel from one end to the other.
Superior Length Stability
Assures V-belts require less re-tensioning and take-up during their service.
Surface Finish
A measure of the roughness of a surface, usually expressed in microinches or micrometers.
Surface Speed
The linear speed of a point on the surface of a rotating shaft, usually expressed in FPM or m/sec.
Surge Pressure
Operating pressure plus the increment above operating pressure that the expansion joint will be subjected to for a very short time period. Surge Pressure is typically due to pump starts, valve closing, etc.
Swelling
The increase in volume or linear dimension of a specimen immersed in liquid or exposed to a vapor.
Synchronous
Generic term used for power transmission drive systems utilizing toothed belts in mesh with grooved pulleys or sprockets. These systems are also referred to as Gilmer or timing.