Calculate the Thermal Range Between Your Shaft and Housing
Our thermal range calculator shows engineers how the material of the bearing, housing and shaft will grow or shrink when in operation.
The top section is based off installation temperatures and ABEC / DIN / ISO standards. The lower section applies the temperature input and calculates how the materials will attempt to grow or shrink.
Note that this information is provided within the free state of the materials. There will be some variation from the below due to resistance between the materials; this should be under consideration.
Quick Tip About Housing Temperature
If you have a standard application and are unsure of the housing temperature, use the ambient temperature of the room that houses your spindle and place that into the temperature field. Add an additional 10°C for the shaft temperature. This 10°C increase for shaft temperature will usually provide a good estimate for the running temperature increase.
Note: High n*dm applications and high load applications may produce more than a 10°C difference between the shaft and housing temperature.
Make sure to check out our shaft and housing tolerance calculator to ensure you get the right tolerance when machining your shaft and housing.
General Application Notes for Precision Bearings
1. The ID of the bearing should rarely float on the shaft. A line fit is an ideal minimum for many applications to prevent inner race slipping.
2. The OD of the bearing should usually have a slight gap during install. This gap will ensure space for heat and centrifugal force expansion.
3. The suggested generic nominal install tolerances are a ~3 micron press fit on the ID and a ~4 micron gap on the OD. This is an “ideal” scenario and can be expensive and/or difficult to machine. Adjust the values for bearing size, speed, temperature, and other possible application specifics.
4. A positive resultant number above implies a GAP where a negative number implies INTERFERENCE.
5. If you have a standard application and are unsure of the housing temperature, use the ambient temperature of the room that houses your spindle and place that into the temperature field. Add an additional 10°C to the shaft temperature to allow for the increase in temperature from when the shaft is in operation. High n*dm applications and high load applications may have a higher temperature delta between the shaft and housing.
6. There are many factors that go into proper tolerancing; bearing size, RPM, temperature, materials, duty cycle, etc. All can play a role in proper tolerancing. This is a guide for general applications. GMN Bearing USA and its partners make no representations or warranties of any kind regarding the tool and information contained on this page. Any use or reliance upon this tool and information shall be at the sole risk of the user and GMN Bearing USA Ltd. shall have no liability whatsoever with respect to any decisions or actions made by the user based on results obtained from this tool and information.
DISCLAIMER: The data and information provided on this page is for general use purposes only. While the intention is to provide accurate information, the calculations performed by these tools/calculators are mathematical estimates only, therefore errors may exist in the supplied information. There is NO WARRANTY OR GUARANTY, expressed or implied, regarding the accuracy of this information or its applicability to your engineering situation. Please consult your own engineering consultant before making any technical decisions.