1. What is TRIBOLOGY?
Tribology originates from Greek word TRIBOS meaning "a rubbing" or friction and word LOGOS – science. Tribology is scientific discipline which researches appearances and processes on interacting surfaces that are in relative motion, i.e. in direct or indirect contact. Basic aim of tribology is to study conditions for optimal conducting of production processes, for energy consumption reduction, reduction of maintenance costs due to machine wear and increase of mechanical system reliability.
In other words, tribology is the study of lubrication.
2. What is the optimal quantity of lubricating grease which is filled into the bearing?
The quantity of lubricant in the bearing is recommended by bearing manufacturer. However, in rare cases the necessary quantity of lubricating grease is over one half of maximum possible quantity that is possible to be filled into the bearing.
3. What does NLGI mark mean in determining the lubricating greases quality?
NLGI - NATIONAL LUBRICATING GREASE INSTITUTE - is the association which defines lubricating greases quality and directly determines type of lubricating greases according to consistency (hardness). In practice, lubricating greases are divided into: semifluid, soft, medium hard and hard lubricating greases.
4. What happens if lubricating greases of different grades are mixed?
If it is the manual lubrication then nothing drastic happens, but in central lubrication big problems, even great damages may happen.
5. In what conditions are special lubricants most frequently used?
They are always used when equipment producer or when application conditions require that: in very low temperatures, very high temperatures, significant influence of water and moisture, impurities, significant presence of vibrations, high speed of revolutions in assembly blocks and very high loads.
6. Are FAM lubricating greases compatible with different sealing materials?
FAM lubricating greases do not have negative impacts on common sealing materials.
7. Are FAM lubricating greases compatible with plastics and elastomers?
Yes, they are compatible with the standardized ones.
1. What do certains marks such as SAE, API, ACEA on engine oil labels mean?
SAE - Society of Automotive Engineers - society that prescribes standards that define engine oil viscosity. Based on these standards, oils are sorted in accordance with viscosity grade which directly influences the application of the oil.
The oils marked with letter "W" (winter) are monograde oils for winter operating conditions (eg. SAE 5W, SAE 10W, SAE 15W...). Among other things, standard efines oil properties in low and in high temperatures, thus reliability of engine start is provided as well as fast engine oiling and oil behaviour during full exploitation. Oils without letter "W" (eg. SAE 10, SAE 20, SAE 30, SAE 40 ...) are monograde oils for summer operating conditions, with properties required for such application. Combination of properties of the two oil types (winter and summer) resulted in multigrade oils which are applied for wide temperature range of operating conditions (eg. SAE 5W-40, 10W-40, 15W-40 ...).
API - American Petroleum Institute - institution that defines engine oil quality levels worldwide. There are two groups of standards:
- API S_ - Oils for four-stroke gasoline engines used in passenger cars and light cargo vehicles.
- API C_ - Oils for highly loaded diesel engines of commercial vehicles.
Letters are added with S and C. Alphabetical growing order indicates higher oil quality.
ACEA - European Automobile Manufacturers' Association - issues three types of standards:
- ACEA A _/B _ - Oils for gasoline and diesel engines of passenger cars and light cargo vehicles.
- ACEA C _ - Oils for vehicles with exhaust gas processing.
- ACEA E - Oils for diesel engines in heavy commercial vehicles.
Apart from the mentioned letters arabic numerals are added. Growing order indicates higher oil quality.
EURO - Exhaust emission is defined by regulations known as EURO standards. This is the area with very strict demands particularly in diesel engines. For example, EURO III standards were published in 2000., EURO IV standards were published in 2004., EURO V standards were published in 2008., and EURO VI standards are expected in 2011.
ILSAC - Association of Japanese car manufacturers, Ford, General Motors and Daimler Crysler publish their own requirements by which necessary engine oil quality level is defined, and they are in accordance with API and ACEA specifications.
For example, ILSAC GF-5 corresponds to quality API SN. Certainly, together with the mentioned standards and specifications, famous car manufacturers have their additional requirements for engine oil quality.
2. What should be paid attention to, when choosing engine oil?
The first and basic prerequisite is to observe the recommendations of motor vehicle manufacturer and those recommendations must be observed. The following also must be taken into account: age of the vehicle, engine condition, driving modes and fuel quality. Of course, change periods differ for different oil qualities, which also must be taken into account.
3. How should I know when to change the engine oil?
This dilema is solved to a greater degree during engine oil selection. Besides the mentioned criteria for selecting engine oil, attention should be paid to oil consumption during exploitation (which is measurable), change in oil smell, possible change in engine sound, increase of engine operating temperature and start itself. These and other empirical observations may be very helpful when determining oil exploitation period for specific vehicle, of course in absence of laboratory checks.
4. What are advantages of synthetic compared to mineral and semisynthetic engine oils?
Compared to mineral oils and to a lesser extent to semisynthetic oils, generally speaking, synthetic oils have better properties regarding:
- antiwear properties,
- thermal and oxidation stability,
- viscosity – temperature characteristics,
- volatility, and therefore consumption,
- coke content, creation of deposits in the engine, oiling of engine,
- exhaust emission
- exploitation life.
5. Can engine oils from different producers be mixed?
Legally speaking, engine oils of different producers, with the same viscosity grade and the same base (mineral, semisynthetic and synthetic) must have the ability to be mixed, i.e. must be compatible. In practice, in such situations one must be careful and such situations should be avoided. Oils of different viscosity grades and different bases should not be mixed.
6. After using synthetic engine oil, may I revert to using mineral oil again?
Yes, it can be done after changing the old oil and oil filter. Their mixing is not recommended.
7. Can there be any problems when switching form mineral to synthetic engine oil?
No, if the old oil and filter are changed. Their mixing is not recommended.
8. What are the advantages of using engine on gas?
It is environment friendly, the driving is more economical, the combustion is better and more complete and engine oil contamination is lower.
9. Do FENIX engine oils reduce fluel consumption?
With application of high quality oils small saving in fuel consumption can be expected.
10. Do synthetic lubricants cause sealings to leak?
That hazard exists only if sealings are not produced from material defined in accordance with world standards for indicated purpose.
11. What must be taken into consideration on lubricants disposal?
The most important issue is environment protection (pollution of water, air and soil must be prevented). All oils must be collected, stored and processed in legally prescribed manner.
12. How big is the actual cost od engine oil?
Cost structure indicates that lubricants are not big expense. For example, total costs of the car that passes 20.000 km annually, are composed as follows:
- Fixed expenses, they amount to 80% (tax, insurance, registration, depreciation) and
- Variable expenses, which amount to 20%.
Structure of variable expenses is as follows:
- Maintenance and repair of the vehicle - 51%,
- Fuel participates with 40%,
- Tyres 8%, and
- Lubricant expenses - only 1%.
Expenses of lubricants which amount to 1% of variable costs are very low i comparison with all other costs. Therefore there is no reason to skimp on choosing the lubricant.
On the contrary, oil quality has special effect on total maintenance costs and with careful selection significant savings can be achieved.
13. What else should be known for proper usage of engine oils?
Proper selection of high quality modern engine oil provides the following:
- Longer interval of oil and filter change.
- Reduced consumption of oil even up to 3%.
- Fuel consumption can be reduced from 3% to 5%, and even more in winter conditions.
- Easy engine start in winter conditions and very fast assembly blocks lubrication (80% of all engine wear happens during engine start, particularly in winter conditions).
- Longer battery life.
- Good engine protection in city drive, i.e. during lower number of revolutions.
- Proper engine operation.
- Maximum power utilization and efficient achieving of desired performances.
In very worn out engines, OEM recommendations are relative in a way. Good solution can be the application of oil which is one viscosity grade above the recommended one. Depending on worn-out degree, lower oil consumption is achieved, better working pressure and sealing. Besides that, potential smaller entering of fuel into oil is achieved and better engine protection is achieved. Often, viscosity grades 20W-50 and 20W-60 are very good solution. Naturally, period of oil exploitation under given circumstances is shortened. Shortening of change period is in the range of 20% to 40% of the prescribed one.
For heavy duty operating conditions in relatively new machines, if longer oil change period is required, semisynthetic and synthetic oils are better option. In contrast to the mineral oils, these oils are more resistant to high temperatures, oxidation and polymerization as well as to acidic combustion products. Their coke value is much less and they have better shear stability, therefore they keep the necessary viscosity longer. They are, certainly, applicable to new mechanization where appropriate viscosity grades are prescribed. Change intervals in such oils are significantly higher and they are economically more payable.
Generally speaking, the ration of engine oil change interval of the same or similar specifications is:
mineral : semisynthetic : synthetic = 1 : 1,5 : 2
Considering that price ratio is more favourable, it is easy to find economic reasons for application of better quality oils.
When choosing between monograde and multigrade oils, in most cases multigrade ones should be selected. Multigrade oils have stable viscosity and they are applicable in all weather conditions. They have the advantage in different driving modes and their temperature is more stable. Monograde oils are applicable in unified exploitation modes, primarily in stationary engines.
Similar recommendation is valid also for transmission oils. Wherever it is possible, multigrade transmission oils should be applied. The most frequently applied grades are SAE 80W-90 and SAE 85W-90.
Oil filter is important factor which significantly influences oil change period. Very frequently it is the weakest point in the oil system, which is sometimes forgotten. Besides the efficiency of filtering and letting oil into circulation flows, which is very important in engine lubrication, oil filter keeps the particles of metal wearing which may have catalytic effect on the process of oil degradation.
1. What are basic functions of cutting fluid?
Basic functions of cutting fluid are cooling, lubrication and chips removal. By cooling and lubrication the temperature which occurred during cutting process is controlled, tools and by chips removal, tool wear is reduced to minimum.
2. How to select the most optimum metalworking products?
The selection of suitable (optimum) metalworking product for certain machining process is complex problem. When solving it, multidisciplinary approach is necessary and the following things must be taken into consideration:
- Machinability of the processing subject material
- Metalworking product compatibility and
- Metalworking product acceptability
Material machinability defines the degree of easiness with which it can be machined and it depends on:
- Type of machining
- Processing subject material type
- Type of tool material and
- Machining conditions (speed of cutting, steps, and cutting depth).
From the viewpoint of material machinability, products with good cooling properties are used:
- In machining with relatively high cutting speeds
- In machining easily workable materials
- In "easy" operations (low cutting resistances) and
- In operations where there are deposits on tools
Emulsions and low concentrate content solutions are used here.
Products with good lubricating properties are used:
- In machining with relatively low cutting speeds
- In machining "difficult" workable materials
- In "difficult" machining operations (high cutting resistances) and
- In operations where high quality of machining should be achieved.
Cutting oils or emulsions are used as well as high concentrate content solutions.
When selecting metalworking product, attention should be particularly paid to their anticorrosion properties especially in operations of machining aluminium, copper and magnesium alloys.
Metalworking product must not stain (leave traces - stains) and must not cause corrosion on machining items, and not only on machined surfaces. Metalworking product should protect machining items from corrosion during cutting, during transportation from one machine to another in the production process and while machining item is waiting in the store house to be built into the product.
Acceptability, from the point of view of operator who performs the machining procedure, is very important characteristics of the metalworking product, which should be taken into consideration when selecting the product for certain machining process. Metalworking products must be clean, must have pleasant odour, during their usage poisonous vapours or gases must not appear and they must not harm the operator`s skin. Emulsions and solutions must be sufficiently stable and resistant to bacteria development, especially in summer months
3. What requirements must be met when selecting metalworking product?
There are primary and secondary requirements which should be met.
Primary requirements are tribological, ecological and economical:
Tribological requirements are based on:
- minimum cutting resistance,
- energy reduction,
- machined surface quality and
- cutting temperature
Lubricant with good tribological properties provides:
- Lower energy consumption in production machines
- Longer life of production machines
- Higher reliability of production machines operation
- Reduced maintenance costs
- Production processes without frequent operation interruptions
- Higher production systems productivity
Ecological requirements are:
- harmlessness to humans (respiratory organs, eyes and skin),
- harmlessness to environment (water, air and soil) and
- decomposition of waste emulsions/ solutions.
Economical requirements include:
- labour costs,
- cutting tool costs,
- production equipment costs and
- metalworking products costs.
Secondary requirements are:
- Product stability during storaging
- Absence of harmful substances
- Absence of skin irritation
- Water miscibility
- Optimum pH values
- Stable emulsions
- Compatibility with "wandering" oils
- Good anticorrosion protection
- Compatibility with sealing materials
- Foaming reduced to minimum
- Good water washout property and
- Good filterability property
4. What are the advantages of lower viscosity oil application?
- Lower taking out of the oil
- Simplified cleaning
- Better cooling
5. What are the advantages of higher viscosity oil application?
- Lower creation of oil mist
- Lower evaporation loss
- Better lubrication on high temperatures
6. What is the basic message on selection metalworking product?
When selecting metalworking product it is important to remember their enormous influence on life expectancy of the tools, energy consumption during cutting process, machined surface quality and machining costs.
Basic goal of every technical system operation is achieving long period of time in which the system works properly without failures. By adequate selection and regular application of lubricant, downtime and maintenance costs can be reduced
7. What should be taken into consideration when selecting optimal cutting oil?
In order to make the right selection of cutting oil, the following thing should be taken into consideration:
- Type of machining process
- Workpiece material
- Machinability: Difficult machinability materials – higher level of additive - Coloured materials: higher level of fatty acid esters and phosphorous materials. (Stainless) steel, difficult machinable Al, titanium..: higher sulphur content. Small pieces / fine machining – lower oil viscosity
- Tools - Tools material, shape and profile of tools
- Cutting modes - Depth, step, speed and inflow of fluid
- Compatibility - With hydraulic and slideway oils
- Cooling system - Fineness and type of filter
- Purity of machined part - Degreaser and cleaning system
- Health and safety - Operator and environment
- Rationalization - Reduction of different types in store house
- Costs - Total operation costs: life expectancy of tools, fluid price efficiency