Contact US

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.

Students Click Here

Width of an O-Ring Groove to an Edge

Width of an O-Ring Groove to an Edge

Width of an O-Ring Groove to an Edge

Good evening everyone,

I'm designing an o ring groove for a part I need to seal, I want to ask what is the recommended width from the edge of the O-ring groove to the other edge of the my part. I set a value of 1.25mm as shown in the picture but im not sure if it's a good width or not.

can you please help me with this matter?

Thank You

RE: Width of an O-Ring Groove to an Edge

Most of ring manufactures have on their website
Their recommended design recommendations.
I took a look at your sketch and I am not sure what I am looking at. Not a typical design.

RE: Width of an O-Ring Groove to an Edge

Well, you could make the edge a zero distance, if you thought nothing would let the oring move past that edge. Seal might or might not function without an edge present, can't tell from a cryptic screenshot from a cad program. Comes down to the retention of the seal, and what stress(es) the seal will put on the part under the worst case pressure differential, plus some margin of safety.

RE: Width of an O-Ring Groove to an Edge

i went through Parker text book to look for this matter but i could not find anything related to the wall or width from the o-ring groove to the hole or slot that would be sealed

RE: Width of an O-Ring Groove to an Edge

Do you know where in Parker textbook i can find information related to the wall thickness of an o ring groove?

this is a picture to illustrate more about what I'm looking for, i would like to know the wall thickness from the groove side to the hole that would be sealed

RE: Width of an O-Ring Groove to an Edge

It is related to the scale of the part.
If this is a part that is a couple of cm wide with a <1mm O-ring as a seal, then a 1mm lip might work fine.
Think of the O-ring seal on the back of a wristwatch.
But if this is larger with any real forces on it then you would need something more robust.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: Width of an O-Ring Groove to an Edge

Is there an internal or external pressure in the part?

RE: Width of an O-Ring Groove to an Edge

There will be no pressure the part is basically a camera which will be used in normal air pressure (1 bar).

but for any future design, is there a way or a standard chart for the size of this lip ?

RE: Width of an O-Ring Groove to an Edge

Okay, if there is no significant pressure differential across the oring, then the only design consideration for the land width is durability in use (is this likely to get banged up if the lid/cover/whatever is opened frequently) and how difficult it might be to form the groove and land repeatably (if it's a milled groove, you might want to keep it thick to absorb cutting forces and not cave in; if alternatively it's a molded feature, you might get away with a much thinner land width). I don't think you will find recommendations in the Parker handbook, it's going to be a gut call.

RE: Width of an O-Ring Groove to an Edge

There are "mill cutting force calculators" online that would help you pick a minimum thickness.

RE: Width of an O-Ring Groove to an Edge

I typically try to leave the 'lip' on the inner side of the o-ring feature as the same width as the o-ring groove itself, for forming reasons. On cast, or injection molded parts, the thinner the lip is the harder it is to create, and if it's too thick you just waste material.

Packaging or other concerns sometimes affect that dimension and could result in changes.

There is no general 'rule of thumb' for this dimension that I'm aware of.

RE: Width of an O-Ring Groove to an Edge

Just remember, the smaller the thickness of an edge.
The easier it will, can get dings.
It's better to have a little extra wall thickness.
Give your self a liberal edge distance.

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! Already a Member? Login


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