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


Over molding a steel bracket

Over molding a steel bracket

Over molding a steel bracket

Hi Everyone,

I am in the process of designing an over molded bracket or more like a lever. The lever is 6 mm thick and 20 mm x 60 mm in size. The over mold thickness is .7 mm. I would like to know what is the minimum draft on the mold? I ask this because I need to maintain a flat area where a pin rides. However, the area would be on a drafted surface. Would I have to add action in the tool to maintain a flat area?


RE: Over molding a steel bracket

Depends on how elastic the overmold is, i.e. if it's closer to rubber, then you can probably get away with the flat (or even an undercut), if it's a harder plastic (e.g. nylon) then perhaps not. Talk to your molder about it.

RE: Over molding a steel bracket

You may well have problems filling a mold with only 0.7 mm plastic thickness. Depending on the material and the length it has to flow, it may freeze off before it fills. Heating your inserts will help. It's possible to have zero or even negative draft, need more specifics.


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.

RE: Over molding a steel bracket

Hi btrueblood and dgallup,

Thanks for all your input on this issue, Unfortunately, I was pulled off this project for a short while.
I will get into the specifics later when I pick the project again.



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!


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