Jump to DN Factor Calculator
Jump to Table 1: DN factor formulas
Jump to Table 2, Grease selector charts: Roller bearings
Jump to Table 2, Grease selector charts: Plain bearings
Jump to Table 2, Grease selector charts: Open gears
What is DN Factor?
DN factor is a value you need in order to determine the correct grease for your bearing and speed. This post shows you how to find the DN factor for the most common bearings.
D stands for diameter, and N stands for speed. The DN factor is therefore a product of diameter and speed. It is obtained by multiplying the average diameter (D + d/2) of a bearing by its revolutions per minute (RPM) and a correction factor that depends on the type of roller element. This will result in a number that allows you to determine what base oil viscosity is needed for that bearing. The precise formula for determining the DN factor varies depending on bearing type. (See Table 1.)
How to Use DN Factor to Determine the Correct Grease for your Bearings
- Calculate the DN Factor of your bearing using the calculator above, or one of the formulas in Table 1.
- Use your answer to choose the correct grease from one of the charts in Table 2.
- Check our Technical Advisor map to find a TA near you to place your order, or just contact Interflon USA at 1-877-FIN-LUBE.
Background
In the early days of industrial machinery, little thought was given to whether a particular grease was the right choice for a particular application, because there were so few types of greases to choose from.
Today, however, there are many different types of greases, each one tailored for a specific application. This is advantageous because the correct grease selection:
- is suitable for bearing operating temperature
- results in the lowest possible energy and re-lubrication costs
- helps obtain maximum component life
- provides maximum protection against corrosion
However, it does complicate the process of choosing the right grease. Interflon seeks to make this process easier by providing the information essential to making the correct lubricant choice.
Interflon manufactures grease for nearly every type of bearing application. If, after looking at these tables, you are still in doubt about which grease is correct for your application, please contact your closest Technical Advisor (TA) or call our main office at (877) FIN-LUBE to ask. We’re always happy to talk!
Table 1: Formulas for Determining DN Factor
Instructions
Identify the correct type of bearing for your application. Then use the formula to the right to calculate the DN factor for that bearing type.
Bearing Type | Formula | ||
---|---|---|---|
Note:A = inner diameter B = outer diameter |
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Open GearDN factor = diameter (mm) x RPM (r/min) |
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Plain BearingDN factor = diameter shaft (mm) x RPM (r/min) |
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Ball BearingDN factor = ((A+B)/2) (mm) x RPM (r/min) |
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Double-row Ball BearingDN factor = ((A+B)/2) (mm) x RPM (r/min) |
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Single-row Cylindrical BearingDN factor = ((A+B)/2) (mm) x RPM (r/min) x 2 |
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Double-row Cylindrical BearingDN factor = ((A+B)/2) (mm) x RPM (r/min) x 2 |
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Single Conical and Spherical BearingsDN factor = ((A+B)/2) (mm) x RPM (r/min) x 3 |
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Double Conical and Spherical BearingsDN factor = ((A+B)/2) (mm) x RPM (r/min) x 3 |
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Needle BearingDN factor = ((A+B)/2) (mm) x RPM (r/min) x 3 |
Chart 2: Grease Selector
Instructions
Taking the DN factor you calculated above, use the chart below to find the correct grease for your bearing.
Roller Bearings
DN factor | Interflon product |
---|---|
DN < 60 000 |
Interflon Grease LS1/2 Interflon Grease OG Interflon Grease LS2 Interflon Food Grease EP Interflon Food Grease LT2 (Low temperature: -45° C/-49° F) Interflon Food Grease HD2 Interflon Food Grease 1 Interflon Grease HTG Interflon Grease HD2 Interflon Fluor Grease |
DN < 120,000 |
Interflon Grease LS2 Interflon Food Grease EP Interflon Food Grease 2 Interflon Food Grease LT2 (Low temperature: -45° C/-49° F) Interflon Food Grease HD2 Interflon Food Grease 1 Interflon Grease HTG (High temperature: >150° C/302° F) Interflon Grease MP2/3 Interflon Grease HD2 Interflon Fluor Grease |
DN < 250,000 |
Interflon Food Grease EP Interflon Food Grease 2 Interflon Food Grease LT2 (Low temperature: -45° C/-49° F) Interflon Food Grease HD2 Interflon Food Grease 1 Interflon Grease HTG (High temperature: >150° C/302° F) Interflon Grease MP2/3 Interflon Grease HD2 Interflon Fluor Grease |
DN < 350,000 |
Interflon Grease MP1 Interflon Grease MP2/3 Interflon Grease HD2 Interflon Bio Grease MP2 |
DN < 500,000 |
Interflon Grease MP2/3 Interflon Grease HD2 |
DN < 680,000 |
Interflon Grease MP2/3 |
DN < 1,000,000 |
Interflon Grease HS2 |
DN > 1,000,000 |
Please contact us to discuss alternate lubrication solutions for bearings with a DN factor of over 1 million. |
Plain Bearings
DN factor | Interflon product |
---|---|
DN < 7,500 |
Interflon Grease LS2 Interflon Grease LS1/2 |
DN 7,500 – 30,000 |
Interflon Food Grease EP Interflon Food Grease 2 Interflon Food Grease LT2 Interflon Food Grease HD2 Interflon Food Grease 1 Interflon Grease HTG |
Temperature | |
Low temps (-45° C/ -49° F) | Interflon Food Grease LT2 |
High temps (>150° C/ 302° F) |
Interflon Grease HTG Interflon Fluor Grease |
Open Gears
DN factor | Interflon product |
---|---|
DN < 10,000 (Extreme loads) |
Interflon Grease OG |
DN < 20,000 (Extreme loads) |
Interflon Grease LS2 Interflon Grease LS1/2 (preferably LS2) |
DN > 20,000 (Heavy to moderate loads) |
Interflon Grease MP2/3 Interflon Grease HD2 Interflon Food Grease EP |
Low temperatures |
Interflon Food Grease LT2 |
To learn more about DN factor, see the Wikipedia article here.
Very brilliant. So well explained.
Thank you for your feedback! We certainly hope the larger community finds it useful.