Industrial Bearing & Engineering Glossary

The Annular Bearing Engineers Committee precision rating system (ABEC 1-9) equivalent to ISO tolerance classes, used primarily in the US market.

A tapered sleeve that allows a bearing with a tapered bore to be mounted on a plain (non-stepped) cylindrical shaft without machining.

A precision ball bearing with a contact angle between the balls and raceways, designed to carry combined radial and axial loads at high speeds.

A mechanical or electromechanical system that delivers precise, timed doses of lubricant to multiple bearing points without manual intervention.

A rolling-element bearing that uses steel balls between inner and outer raceways to reduce rotational friction and support radial and axial loads.

The kinematic viscosity of the base oil component in bearing grease, measured in mm2/s (cSt) at 40C, which determines the lubricating film thickness.

The retainer component that separates and guides the rolling elements within a bearing, preventing ball-to-ball or roller-to-roller contact.

A bearing internal clearance class with larger-than-normal radial play (C3 > CN), specified for applications with temperature differentials or tight shaft fits.

The alphanumeric part number system used by bearing manufacturers to encode bearing type, size, clearance, cage, seal, and special features.

A systematic investigation of failed bearing components to determine the root cause and implement corrective actions to prevent recurrence.

A semi-solid lubricant combining base oil, thickener, and additives, specifically formulated to reduce friction and protect bearing surfaces.

A cast iron, steel, or stainless steel enclosure that supports and protects a bearing while providing a mounting interface to the machine frame.

An integral or separate sealing element that prevents contaminant ingress and lubricant leakage in a bearing assembly.

The manufacturing precision grade of a bearing (Normal, P6, P5, P4, P2), defining dimensional and running accuracy per ISO 492.

A high-performance bearing using silicon nitride (Si3N4) ceramic balls or rollers, offering higher speed, lower friction, and superior corrosion resistance.

The continuous or periodic measurement of equipment parameters (vibration, temperature, oil analysis) to assess bearing health and predict remaining life.

A high-capacity roller bearing with straight cylindrical rollers, offering excellent radial load capacity and the ability to accommodate axial shaft displacement.

The constant radial load a bearing can theoretically endure for one million revolutions of the inner ring, per ISO 281, used to calculate L10 life.

Membership in the European Power Transmission Distributors Association, a quality certification for authorised industrial distribution companies.

A rotating metal disc that uses centrifugal force to throw off contaminants before they reach the bearing seal, acting as a first line of defence.

A heating element installed in diesel engine pre-combustion chambers that heats the air to assist cold starting and reduce white smoke emissions.

The ability of two different bearing greases to be mixed without adverse effects on consistency, oil separation, or lubricating performance.

A manual, pneumatic, or battery-powered tool used to deliver grease through a zerk (grease nipple) fitting into a bearing housing for re-lubrication.

A spark plug specification that indicates its ability to dissipate combustion heat, determining whether it runs 'hot' (retains heat) or 'cold' (dissipates quickly).

A seal designed for hydraulic cylinders and systems, including piston seals, rod seals, wipers, and guide rings that withstand high pressure.

An electromagnetic transformer that converts the battery's 12V to 20,000-40,000V needed to create a spark across the spark plug electrode gap.

An electromagnetic device that uniformly heats a bearing to expand it for interference-fit mounting on a shaft without damaging the bearing or lubricant.

The inner raceway component of a bearing that presses onto the shaft and provides the running surface for rolling elements.

A premium spark plug with an ultra-fine iridium center electrode (0.4-0.6mm) that provides superior ignition, longer life, and better fuel efficiency.

The international standard that defines the method for calculating the basic dynamic load rating and rated life (L10) of rolling bearings.

The calculated number of revolutions (or operating hours) at which 90% of a group of identical bearings will still be in service under specified conditions.

A non-contact seal that creates a tortuous path of grooves and chambers to prevent contaminant ingress without physical contact with the shaft.

A bearing that provides smooth, low-friction motion along a straight line, used in CNC machines, 3D printers, and automated manufacturing equipment.

The average elapsed time between consecutive failures of a repairable system, used as a key reliability metric in maintenance planning.

A precision shaft seal used in pumps and mixers that maintains a near-zero-leakage barrier between rotating and stationary seal faces.

A precision small-format bearing with bore diameter under 10mm, used in dental handpieces, drones, instruments, and micro-motors.

A compact roller bearing with long, thin cylindrical rollers (needles) that provides high radial load capacity in a minimal cross-section envelope.

The National Lubricating Grease Institute consistency classification (000 to 6) that indicates grease stiffness, with Grade 2 being the standard for rolling bearings.

A circular cross-section elastomer ring used as a static or dynamic seal in hydraulic systems, flanges, and bearing covers.

A lubrication method that delivers a fine mist of oil droplets in an air stream to bearing contact points, used in high-speed and high-temperature applications.

A radial lip seal that prevents lubricant leakage and contaminant ingress around a rotating shaft, typically made from NBR, FKM, or PTFE.

The stationary raceway component of a bearing that fits into the housing and contains the rolling surface for balls or rollers.

A manufacturing KPI that measures the percentage of planned production time that is truly productive, combining availability, performance, and quality.

A pedestal-mounted bearing housing unit (UCP series) that bolts to a flat surface and supports a shaft with a self-aligning insert bearing.

A maintenance strategy that uses condition monitoring data and analytics to predict equipment failures and schedule maintenance at the optimal time.

The calculated time period between grease replenishment events for a bearing, based on speed, temperature, load, and bearing size.

A bearing that uses cylindrical, tapered, or spherical rollers instead of balls, providing higher load capacity for heavy-duty industrial applications.

The balls, cylindrical rollers, tapered rollers, needles, or spherical rollers inside a bearing that transfer load between the inner and outer raceways.

A structured problem-solving method used to identify the fundamental cause of bearing failures and equipment breakdowns, not just the symptoms.

A bearing with a spherical outer raceway that accommodates shaft misalignment and deflection, available as self-aligning ball or spherical roller types.

The process of aligning two coupled rotating shafts so their centerlines are collinear, minimizing vibration, bearing loads, and seal wear.

An ignition component that delivers an electrical spark across an electrode gap to ignite the air-fuel mixture in a petrol engine combustion chamber.

The product of bearing speed (RPM) and mean diameter (mm), used to assess lubrication requirements and determine if a bearing is in a high-speed regime.

A self-aligning bearing with barrel-shaped rollers on a spherical outer raceway, designed for heavy loads and angular misalignment in industrial equipment.

The maximum radial load a non-rotating bearing can withstand without permanent deformation of rolling elements or raceways, per ISO 76.

A bearing with conical rollers that can support large combined radial and axial loads, widely used in automotive wheel hubs, differentials, and gearboxes.

A bearing specifically designed to handle axial (thrust) loads along the shaft axis, available in ball and roller configurations.

The complete lifecycle cost of a bearing including purchase price, installation, lubrication, monitoring, downtime, and replacement over its service life.

A rubber seal that rotates with the shaft and seals axially against a stationary housing face, providing contamination protection for bearings.

A predictive maintenance technique that measures and analyzes bearing vibration signatures to detect early-stage faults before catastrophic failure.