Smart questions
Smart answers
Smart people
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Member Login




Remember Me
Forgot Password?
Join Us!

Come Join Us!

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

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

Donate Today!

Do you enjoy these
technical forums?
Donate Today! Click Here

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.
Jobs from Indeed

Link To This Forum!

Partner Button
Add Stickiness To Your Site By Linking To This Professionally Managed Technical Forum.
Just copy and paste the
code below into your site.

CR 12L14 internal stresses causing bowing after machining shaftHelpful Member!(2) 

dfoxengr (Automotive)
29 Mar 12 16:02
I am having some issues with keeping a machined 12L14 shaft straight after machining. The shafe is about 3/8" and a flat of over half the diameter is machined out of a section of the shaft in order to create a spot for a plate to rest on. While not being the best idea to cut over half the mat'l thickness out, that is what I have to work with and it can't be changed.

After these are machined there is a bow in the shaft (always away from the cut) and each shaft has to be straightened which is time consuming.

I am wondering if there is another material I can use that will have less internal stress but still be machinable. These are also moly or teflon coated afterwards.

Thank you.
dgallup (Automotive)
30 Mar 12 8:48
I would stress relieve before machining.

----------------------------------------

The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.
 

metengr (Materials)
30 Mar 12 9:05
Agree with the above recommendation.
 
Helpful Member!  TVP (Materials)
30 Mar 12 9:34
dfe,

You are almost certainly using cold-drawn bars as the starting material.  When you make the large cut, it relieves the stresses that have been induced by the cold drawing operation.  Options to pursue include the following:

1. Stress relieve prior to machining as suggested previously, or purchase the bars already stress relieved.
2. Use hot rolled bars instead of cold-drawn.
3. Use cold-finished bars that do not involve drawing, ie turned/peeled or turned and polished if you need improved surface.  Other options exist (use link below for more info):

http://www.cfsbi.com/resources.aspx

 
Helpful Member!  dfoxengr (Automotive)
30 Mar 12 11:45
Yes they are cold drawn bars. Thank you all for the suggestions.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!

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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close