Re 'satin' finish terminology. The finish so clearly described by
gciriani is generally called 'grained satin' or 'brushed satin,' a particular subset of satin finishes, in U.S. industries (luxury accessories may be an exception).
Satin finish is defined as
“A diffusely reflecting surface finish on metals, lustrous but not mirrorlike. One type is a butler finish.*”
--
ASM Handbook, vol. 5, Surface Engineering (1994).
* with fine, parallel lines.
Coatings, both metallic & non, can also have satin finishes.
Some examples:
Satin finish paints & varnishes; e.g.,
Chromium and nickel plating solutions are available which for matte, satin (semi-bright) and bright plating. Differences are due to solution additives known as brighteners. For satin nickel:
'Satin' and 'fine-grained satin' anodized aluminum have separate IBM finish codes (graining is performed prior to anodizing):
41-201
Anodize (satin finish) water sealed (sulfuric acid electrolyte), 5 micrometers minimum
IBM M-H 6-4220-000, 9808
41-208
Anodized-fine grained satin finish, (suitable for silk screening), 5 micrometers minimum, (decorative).
IBM M-H 6-4220-000, 9808
Chromium/nickel & chromium/nickel/copper plating is available in satin finish (aka. semi-bright). Not grained; note that ASTM B456 considers substrate scratches to be defects.
41-041
Plating, chromium, dull. On steel, copper, and copper alloys: nickel 8-13 micrometers, chromium 0.25-2.5 micrometers...
IBM M-H 6-4104-100, 9808
41-043
Chromium plating, satin. On steel, copper and copper alloys: nickel 8-13 micrometers, chromium 0.25-2.5 micrometers...
IBM M-H 6-4104-300, 9808
ASTM B456, B183, B242, B252, B253, B281, B650, B177
ISO 1456, ISO 1457
41-045
Chromium plating, hard, thickness to be specified.
IBM M-H 6-4104-500, 9808
41-046
Chromium plating, polished On steel, copper, and copper alloys: nickel 8-13 micrometers, chromium 0.25-2.5 micrometers...
IBM M-H 6-4104-600, 9808
My experience with satin and grained satin finishes is mostly with aluminum and stainless steel. Satin finishing includes light etching of machined aluminum prior to anodizing & light bead blasting of stainless, used for hiding machining scratches & fingerprints. Graining is mostly touch-up of parts fabricated from grained sheet. Air-powered linear sanders, abrasive belts and wire wheels are used.
Polishing of steel is performed prior to plating. Wire brushing can generally be used for cleaning prior to painting. I recommend against satin or other roughening as a final finish on steel (it increases rusting) unless the part is continuously lubricated.
Also, wire brushing is most suited to softer alloys (Al, Cu-based, precious metals, Zn), while coated abrasives are better for steels and other hard alloys. Of course, brushing can follow abrasive use.
Mass finishing methods have enough variables to produce a continuous range of finishes, from matte to mirror.
Suitable finishing methods for
linamar's part depend upon its geometry. If a grained surface is desired, often best to start with grained material. Then, only need to touch-up after fabrication.
Cheers,
Ken