Specifying a surface finish to a region of a face
Specifying a surface finish to a region of a face
(OP)
Hi,
We have a cylindrical part, a tube I want to bore out to 295 I.D x 845 Long.
On one end I want to specify a surface finish to a region of the I.D, say up to 50mm in, as this is going to be a sealing face.
The surface finish of the remainder of the bore is not important, so long as it's of an appropriate quality to maintain the dimensional constraints (which are forgiving).
So my question is, what would be a legitimate way of conveying this on an engineering drawing?
Thanks in advance.
We have a cylindrical part, a tube I want to bore out to 295 I.D x 845 Long.
On one end I want to specify a surface finish to a region of the I.D, say up to 50mm in, as this is going to be a sealing face.
The surface finish of the remainder of the bore is not important, so long as it's of an appropriate quality to maintain the dimensional constraints (which are forgiving).
So my question is, what would be a legitimate way of conveying this on an engineering drawing?
Thanks in advance.





RE: Specifying a surface finish to a region of a face
What standard are you working to?
In ASME world you can use dots with letters to create “from – to” requirement in the way similar to specifying Profile tolerance A<----->B.
Also you can separate areas with different surface requirement with the thin line accompanied with dimension; then reference it like “Ra 63 .50 width” or something like that.
Another option is to associate surface texture with the dimension, as: “.247/.249 thru, .2500/.2505 .50 deep Ra 16
ISO recommends using chain line with dimension to designate area that requires special treatment. ASME uses chain line for same purpose, so it will be understood, even if it’s not in the book.
RE: Specifying a surface finish to a region of a face
We're working to ISO. I think the chain line, dimension, and a surface symbol attached to the dimension is the way to go. That would be clear to me if I were reading the drawing..
Thanks again, Alan
RE: Specifying a surface finish to a region of a face
Chris
SolidWorks 11
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RE: Specifying a surface finish to a region of a face
Jim Sykes, P.Eng, GDTP-S
Profile Services www.profileservices.ca
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