Smart questions
Smart people
 Find A ForumFind An Expert
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Remember Me

Are you an
Engineering professional?
Join Eng-Tips now!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Just copy and paste the

#### Feedback

"...Over the past year I have found your site to be EXCELLENT. Never have I been able to find so many answers to such vast problems and it is an excellent service..."

#### Geography

Where in the world do Eng-Tips members come from?

# Rate of Freeze-fitting shrinkage

 Forum Search FAQs Links Jobs Whitepapers MVPs
 mechanicalhead (Mechanical) 20 Feb 12 10:38
 HiI work for an excavator bucket manufacturing company and we do a lot of Freeze-fitting on the bushes. I have come across a continuous issue regarding the fitting of some of the bushes as we can't work out how the bushings behave when frozen i.e. how much they shrink by, using liquid Nitrogen. Most of the bushes are made out of phosphor bronze or steelI was wondering if there is a way to predict/work out the shrinkage rate of such material over a given diameter and wall thickness so that we could work out the tolerances accordingly.
 TVP (Materials) 20 Feb 12 11:16
 Lots of available information on this topic:http://www.engineeringtoolbox.com/assembly-shrink-fits-d_951.htmlhttp://www.ameritherm.com/PDFs/shrinkfitcalcs.pdfhttp://www.tribology-abc.com/calculators/e6_2.htm
 Cockroach (Mechanical) 20 Feb 12 11:46
 For sure, you're realling with a heat transfer and thermal strains.Look at a first year course in statics, deformation for example, and you will come across the equation: d=a(T')L.  Deformation is a function of temperature change and length of the member.  The linear coefficient is a number particular to the material properties in question.Good luck with it. Regards,Cockroach
 dhengr (Structural) 20 Feb 12 15:46
 Search this Mech. forum for shrink-fit threads/discussions.  Just a month or so ago there was quite a lengthy thread an the topic.  thread404-312505: thermal expansion: hole dia shrinks when part expands?  In part, the discussion had to do with, what happens if you cool a bushing, does the outside dia. shrink and the inside dia. expand, or shrink also?  It has to do with volumetric change or length (circumferential) change due to temp. change.  Or, vis-a-versa, if you heat the bushing.  And, we seem to understand this better when we are just talking about a 12" long steel rod.  Now, form this rod into a ring and do the same thought experiment.  Look up Lame's equations and shrink or press fits in any good Strength of Materials, Machine Design or Theory of Elasticity books.  Another thread   thread404-314076: Torque Capability Of an Intereference fit joint.

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!