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Participant

Join Date: Jan 2017
Posts: 4

Bearing Pocket Dimensions

01/27/2017 5:51 PM

I'm working on a project and need to press fit a bearing in a pocket. The baring OD is 1.125 +.0000/-.0004.

What is the standard on this. Should I machine the pocket to 1.1246?

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Guru

Join Date: Oct 2008
Posts: 39662
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#1

Re: Bearing pocket dimensions

01/27/2017 5:59 PM

Go to your bearing manufacturer's website and look at the tables for your bearing.

Things like materials, environmental and required tolerances for those conditions will determine your tolerances.

There's also the option of an undersized pocket that gets heated and fitted with a cold bearing to attain the required retention.

Contact your bearing maker, otherwise you are taking a chance on premature failure.

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Participant

Join Date: Jan 2017
Posts: 4
#2
In reply to #1

Re: Bearing pocket dimensions

01/27/2017 7:07 PM

It's a McMaster bearing. Don't think you can get too much info.

https://www.mcmaster.com/#60355K704

I guess I'm going to have to try and see.

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Guru

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Posts: 39662
Good Answers: 1573
#4
In reply to #2

Re: Bearing pocket dimensions

01/27/2017 7:32 PM
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Guru

Join Date: Apr 2010
Posts: 5628
Good Answers: 559
#3

Re: Bearing pocket dimensions

01/27/2017 7:29 PM

Here is some information. I don't know if it will help...

"Bearing Fit Chart - Shaft and Housing

Search Our Bearing Products

For further assistance with bearing selection and design, please feel free to contact our engineering team or look at our online catalog .

The following tables are a guide for establishing shaft and bearing fits for miniature and instrument bearings when the expansion coefficients of the shaft and housing are similar or when the operating temperature differential between them is nominal. In other conditions, modification in fits and internal clearance may be required.

Radial Clearance Range
Operating
Conditions
LoadSpeedShaft DiameterAverage FitFit RangeRadial LoadThrust Load
Springs
Rotating ShaftLightLowB- 0.0002
B- 0.0004
0.0002L0
0.0004L
K25K36 TO K58
Light
Medium
High
Low to High
B- 0.0001
B- 0.0003
0.0001L0.0001T
0.0003L
K36K36 TO K58
HeavyHighB- 0.0000
B- 0.0002
Line to Line0.0002T
0.0002L
K36K58
Stationary ShaftNormalLow to HighB- 0.0002
B- 0.0004
0.0002L0
0.0004L
See Rotating Housing
B = Nominal Bearing BoreL = Loose FitT = Tight Fit
Radial Clearance Range
Operating
Conditions
LoadSpeedHousing DiameterAverage FitAverage FitFit RangeFit RangeRadial LoadThrust Load
Springs
Rotating HousingLightLow to High
D-0.0001D- 0.0000
D-0.0003D- 0.0002
0.00005TLine to Line0.0002L
0.0003T
0.0002L
0.0002T
K36K58
Medium to HeavyLow to high
D- 0.0002
D- 0.0004
D- 0.0001
D- 0.0003
0.00015T0.0001T0.0001L
0.0004T
0.0001L
0.0003T
K36K58
Stationary HousingLight to HeavyLow to HighD +/-0.0002
D- 0.0000
0.00025L0.0002L0
0.0005L
0
0.0004L
See Rotating Shaft
D = Nominal Bearing ODL = Loose FitT = Tight Fit
Light LoadC/P < 25Low Speed> 5000 RPM
Medium LoadC/P 15-25High Speed> 1500 RPM
(Bearings w/OD <= 3/8")
Heavy LoadC/P > 15High Speed> 3000 RPM (Bearings w/OD > 3/8")
C = Dynamic Road RatingP = Radial Equivalent Load

* For closer running accuracy or reduced axial play K13 internal clearance may be used provided that the fit of the outer ring is line to line or looser

** For closer running accuracy or reduced axial play K25 internal clearance may be used provided that the fit of the outer ring in the housing is line to line or looser.

Consult our Engineering Department for unique applications.

Read more: http://www.pacamor.com/technical/shafthousing.php#ixzz4X0mXxeQM"

http://www.pacamor.com/technical/shafthousing.php

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Guru
Engineering Fields - Aerospace Engineering - Member United States - Member - Army Vet in the aviation industry

Join Date: Mar 2008
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#5

Re: Bearing Pocket Dimensions

01/28/2017 11:02 PM

If you are going to continue to do any machining work, buy this:

Machinery Handbook

It has all those answers you need to have handy. I got my MH edition in 1966 when I started my apprenticeship and will probably be buried with it.

Hooker

PS - I don't have an affiliation with Amazon for pushing this book.

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Guru

Join Date: Mar 2011
Location: Sebastopol, California
Posts: 828
Good Answers: 35
#6
In reply to #5

Re: Bearing Pocket Dimensions

01/28/2017 11:27 PM

All of my first programs solved formulas from the 18th edition of the MH bible. The last one (for that machine) solved for the volume of an ellipsoid given three perpendicular axises relative to the the major and minor dimensions of the ellipsoid.

I wrote it in assembly language to fit nicely into the 2k of memory the machine had in 1977. I was 13!

I have that edition on my Christmas list. The one I used was my dad's and nobody knows where it went.

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Participant

Join Date: Jan 2017
Posts: 4
#7

Re: Bearing Pocket Dimensions

01/29/2017 12:03 AM

Thank you all of you guys, I'm still doing some reading about bearings. I'm not in a rush to do this so I can take some time.

I'll post again if need more advice.

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Power-User

Join Date: Dec 2016
Location: Baytown Tx. USA where you get your gasoline,chemicals,plastics and floods
Posts: 259
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#8

Re: Bearing Pocket Dimensions

01/29/2017 1:46 PM

1.1255. look up TPD. Also it depends on the bearing temperature and material expansions at temperature.

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Associate

Join Date: Jan 2010
Location: Adelaide South Australia
Posts: 39
#9

Re: Bearing Pocket Dimensions

01/29/2017 3:29 PM

Interference fit .001 per inch of diameter

peugeot man

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Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 18744
Good Answers: 330
#10

Re: Bearing Pocket Dimensions

02/09/2017 8:22 AM

You have to determine the type of fit you need.

Don't use the Machinery's Handbook for fits and tolerances, use the bearing manufacturers, you can get this information from the bearing manufacturer, SKF for example.

Now if your on a project,.. school, personal or for work. You'll need to know and understand the type of fits from the bearing manufacturer that you require, at first look, its a little difficult to read but you get adjusted after awhile.

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