Surface Finish Help (not waterblock related)
 

Hopefully someone knowlegeable in machining can help me with this non-watercooling issue.
The part drawing specifies an average grinding finish of 1.6 microns and a maximum variance of 6.3 microns.
The actual part seems to have a pitted surface and seems quite rough.

Any idea if the part looks like it matches the drawing spec.?

who knows what average means w/o limits ?
Steve at PolarFlo is expert in such

The way it was worded to me was:

the average is 1.6um
and distance between Max and Min. is 6.3um


Don't know if that's going to make any difference since it's hard to judge by the photo.

im guessing that its average roughness is 1.6 um.

Variance describes the height difference along the surface as im guessing that this is for some kind of piping. Ie lowest point is 6.3um below top point with everything all square. This to stop pipe misalignment im guessing.

Can you just use a gasket?

I'm confused. Did you make the part or was it supplied as a sample?

I'm in the middle between the part manufacturer and the end user.
The end user won't accept the part because of the surface condition.
I'm trying to determine if the part meets it's design spec. The part maker says it does.

In which case probably best to get an ISO or some kinda book out on drawing specs and make sure everything is spot on.

I'll depart from my normally hidden mode.

Surface roughness is a fractal characteristic --- what the heck does that mean?! :mad: It means the measurement is dependent on the tool (typically stylus size) used to measure the average.

The specification should state the measurement and the tool used in the measurement of the average quoted. Otherwise the average and variance are not unique. The requestor has given you a specification that will depend on what measurement tool you use and there a several answers.