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!

*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.

Jobs

steering components (light duty truck)

steering components (light duty truck)

(OP)
i was going to send out a steering arm from a 3/4 ton diesel pickup for material analysis, i was just wondering if someone could enlighten me so that i could save some time.

i suspect that the piece is forged, but i was wondering if the piece needs to be forged or not.

RE: steering components (light duty truck)

Usually a piece like that is forged.  This is good for fatigue strength issues (uniform composition and microstructure, smooth grain flow, lack of porosity, lack of sharp edges or other stress concentrators, etc.).  Pieces like this could be made from castings or sheet metal fabrications, but they would need to overcome the issues related to fatigue.

Regards,

Cory

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

RE: steering components (light duty truck)

Forgings generally lack sharp detail as the metal does not flow as well as when cast.

Also forgings need to be struck in a way that the "hammers"? can strike and retract without getting stuck on any undercuts, so there will always be some draft angle apparent.

The parting line will be a blunt flat bump, not a sharp edge.

More complex shapes may be struck from different directions with different hammers to overcome the no undercuts problem in some cases.

To tell the difference between cast iron and steel, run a file over an edge. The steel will peel of shavings while the iron will powder.

Both tests are easier with experience or by direct comparison to known samples.

For detailed composition analysis you will need lab tests. In my lab days they would have used an Elmer Perkins atomic absorbtion spectrophotometer, but that was 30 or 40 years ago. Times may have changed.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

RE: steering components (light duty truck)

Most steering arms, especially if there some curvature to the design, will be forged. The arms are usually quench-and-tempered alloy steel and high wear areas may be induction hardened. If it is a straight arm it possibly could be made from bar stock provided the reduction ratio is high enough.

RE: steering components (light duty truck)

Another simple way of distinguishing castings from forgings (but that wasn't the question,  was it?) is to hit the suspect piece with a hammer,  and listen to it.

Forgings ring,  castings do not.

RE: steering components (light duty truck)

The OP triple posted slightly different but heavily overlapping questions.

The how to tell the difference was in another thread. I answered it all here to keep it in one place.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.

RE: steering components (light duty truck)

I figure generally the geometry of a part can (and should) be changed to allow the use of any particular material. In fact, many of the part failures I've dealt with could easily have been avoided with slightly "better" geometry using the same old material. Airplanes can be made of wood or titanium.  There are lots of strong, ductile casting matarials, but some weak brittle ones too.

Here is a picture of a cast nodular iron (ductile) claiming to be stronger than some unknown stock part .
http://www.rockstomper.com/images/products/axles/60knuckles/dedenbear/ded6005.jpg
the steering arm portion is faired smoothly and massively into the main knuckle.

Here is a picture of steering arm that needs to be a forging.http://www.pozziracing.com/Media/camaro_outersteer_arm_short.jpg

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


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