×
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

Clutch Pressure Plate Material

Clutch Pressure Plate Material

Clutch Pressure Plate Material

(OP)
Anyone know what materials are used for automotive clutch pressure plates? Are they mostly cast iron, or are some steel alloys used?

RE: Clutch Pressure Plate Material

Passenger cars, light trucks, and even larger trucks use gray cast iron for the clutch pressure plates.  A typical alloy is a lamellar pearlitic gray iron like G11H20b according to SAE J431a.  Here is an excerpt from SAE J431:

G11H20b (formerly G3500b)
Brake drums and clutch plates for heavy-duty service where high carbon and high hardness are both required to minimize heat checking and provide higher strength.

RE: Clutch Pressure Plate Material

(OP)
Yes, I was aware of SAE J431, which is why the words "cast iron" figured prominently in my question.

RE: Clutch Pressure Plate Material

Steve,

Sorry about that, I was just trying to be precise with the specific grade of gray cast iron typically used.  I realize you are extremely knowledgeable on automotive materials, etc.  It is my understanding that essentially all high volume automotive applications use cast iron pressure plates, but I am not completely familiar with what our competitors do.

RE: Clutch Pressure Plate Material

(OP)
Thanks.

I should have been more specific in my question,referenced the SAE spec and should have asked about other potential materials.

RE: Clutch Pressure Plate Material

Glad, that this thread has been resurrected. I wanted to add CG irons and also that in some military vehicles, I have seen alloy steel plates being used. Though gray iron was always  considered as candidate material for this application.

RE: Clutch Pressure Plate Material

(OP)
Yes, Arunmrao, steel plate is where I seem to be heading, as my client (gratis) does not have the wherewithal for even a small production run of castings. Based on availability, 4140 and 1144 seem to be the main candidates. Another possibility might be some sort of flame spray coating on a 50ksi HSLA steel ring or even a T-1 ring.

RE: Clutch Pressure Plate Material

swall;
I think your idea of using T-1 material has merit.

RE: Clutch Pressure Plate Material

swall,

Is the clutch assy for an automatic or manual transmission?  AT clutch plates are usually wrought steel, not cast iron.

Since clutches are usually sized based on heat loads, your particular pressure plate material selection will need to take into account the surface temperatures that the pressure plate will experience during operation.  The material and heat treatment should have adequate margins for safe operation at those temps combined with any mechanical loads.

Before you select a material, I'd suggest a quick thermal analysis.  Estimating the input heat loads at the friction interface is fairly straightforward.  The more difficult part is the heat transfer rate away from that surface, through the pressure plate structure, and into whatever local atmosphere it's operating in.

Good luck.
Terry

RE: Clutch Pressure Plate Material

(OP)
Thanks, Terry. Application is manual transmission and this is basically a reverse engineering job. Original piece (which the OEM has discontinued)is a steel forging, and I plan to mimic it as much as possible using a part fab'ed from steel plate. As the production quantities will be small, my client does not have the deep pockets to procure forgings or castings.

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