×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • 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!
  • Students Click Here

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

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Surface Finish Requirements 12-16uinch

Surface Finish Requirements 12-16uinch

Surface Finish Requirements 12-16uinch

(OP)

I need to have a 3/8" round bar finsihed with a surface finsh of 12-16 microinches.  Is this something that is going to be achievable using 8620 or 4340 without being heat treated and being ground.  The part would be machined on a lathe.

Is there a rule of thumb on what surface finish is possible according to the hardness.  Or are the two related?




 

RE: Surface Finish Requirements 12-16uinch

If it's one piece, you might turn it slightly oversize and polish to get the finish.  For a production run, I think you'd be better off adding a grinding operation.

Software For Metalworking
http://closetolerancesoftware.com
 

RE: Surface Finish Requirements 12-16uinch

Hardness and surface finish are not related.  Those two alloys can achieve the stated roughness.

RE: Surface Finish Requirements 12-16uinch

(OP)
CoryPad, the surface finish is more related to the material composition rather than hardness, correct?

 

RE: Surface Finish Requirements 12-16uinch

To get that type finish you should start with a clean steel. A common name in the trade is Aircraft Quality especially with the 4000 series materials.

Could you start with a TGP bar like Mirraloy from Associated Steel. We used this material in place of a 4140,4130,3140, along with 4340 on some parts.

http://www.associatedsteel.com/pdf/09-10.pdf

RE: Surface Finish Requirements 12-16uinch

No, the surface finish is a function of the manufacturing processes.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

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!


Resources