Lesson 1Standards and terminology: ISO cleanliness codes, ASTM, NLGI, DIN/ISO references relevant to maintenanceThis lesson explains main lubrication standards and terms used in Eritrean industry, covering ISO cleanliness codes, ASTM and DIN/ISO tests, and NLGI grades, helping clear talk and proper specs in maintenance work.
ISO particle cleanliness code structureASTM test methods for lubricantsDIN and ISO viscosity classificationNLGI grease consistency numberingReading lube labels and data sheetsLesson 2Lubrication regimes: boundary, mixed, elastohydrodynamic, hydrodynamicThis lesson describes boundary, mixed, elastohydrodynamic, and hydrodynamic lubrication types, relating film thickness to surface roughness, load, and speed, and how knowing the type guides lubricant choice and work habits.
Stribeck curve and key parametersBoundary lubrication characteristicsMixed lubrication in real contactsEHL in rolling element bearingsFull hydrodynamic film conditionsLesson 3Lubricant base stocks: mineral, PAO, ester, PAG — properties and selection criteriaThis lesson looks at main lubricant base types like mineral, PAO, ester, and PAG oils, comparing their physical and chemical traits, oxidation resistance, seal fit, and cost to pick the right one for different factory jobs.
API mineral base oil groupsPAO synthetics: strengths and limitsEster fluids: benefits and cautionsPAG fluids and water-mixable typesMatching base stocks to applicationsLesson 4NLGI consistency for greases and how consistency affects pumpability and film formationThis lesson covers NLGI grease grades, how cone penetration shows hardness, and how consistency impacts pumping, channeling, and film build in bearings and central systems under different heat and speeds.
Cone penetration and NLGI gradesConsistency vs pumpability in linesChanneling and grease distributionEffect on film thickness in bearingsTemperature impact on consistencyLesson 5Contamination effects: particulate, water, and incompatible lubricants — consequences and limitsThis lesson shows how dirt particles, water, and wrong mixed fluids harm lubricants and parts, covering failure types, cleanliness goals, water limits, and simple ways to check, stop, and fix contamination on the job.
Particle-induced wear mechanismsWater contamination sources and limitsEffects of mixing foreign lubricantsCleanliness targets and ISO codesFiltration and dehydration practicesLesson 6Viscosity fundamentals: viscosity, viscosity index, ISO VG, SAE grades, temperature effectsThis lesson builds understanding of viscosity changes, viscosity index, ISO VG and SAE grades, and heat-viscosity links, teaching how to pick and check right viscosity for bearings, gears, and hydraulic setups.
Dynamic vs kinematic viscosityViscosity index and its significanceISO VG grades and selection rulesSAE engine and gear oil gradesTemperature–viscosity charts and toolsLesson 7Additives: anti-wear (ZDDP), EP, antioxidants, rust/corrosion inhibitors, anti-foam, detergentsThis lesson details common lubricant additives like anti-wear, EP, antioxidants, rust inhibitors, anti-foam, and detergents, explaining what they do, their limits, and how they affect lubricant choice and lifespan.
Anti-wear and EP chemistry basicsOxidation control and antioxidantsRust and corrosion inhibitor rolesAnti-foam and air release additivesDetergent and dispersant actionsLesson 8Basic lubricant compatibility and mixing rules (base oil and thickener compatibility)This lesson covers lubricant mixing rules, focusing on base oil types and grease thickeners, reading compatibility charts, mixing risks, and safe switch methods to avoid sludge, softening, or seal harm.
Base oil family compatibility basicsGrease thickener compatibility matrixRisks of mixing incompatible lubricantsFlushing and changeover best practicesUsing OEM and supplier guidanceLesson 9Principles of friction, wear, and lubrication mechanismsThis lesson introduces friction and wear basics, covering adhesive, abrasive, and fatigue wear, and how lubrication builds protective films to keep surfaces apart and lengthen part life.
Types of friction in machine elementsAdhesive, abrasive, and fatigue wearSurface roughness and contact areaRole of lubricant films in protectionRelating wear modes to field symptomsLesson 10Types of lubricants: oils, greases, solid lubricants, and their general usesThis lesson sorts oils, greases, and solid lubricants, explaining their makeup differences, common uses, and how method, speed, load, and surroundings guide lubricant form choice in factory gear.
Liquid oils and circulation systemsGreases for bearings and couplingsSolid lubricants: MoS2 and graphiteDry-film and boundary lube coatingsSelecting form based on duty cycle
