Grinding, polishing,
buffing, satin finishing, media blasting, welding, and
fabrication of many different metals. These metals include:
aluminum, steel, stainless steel, copper, and brass.
Types of
finishes:
#3 Finish:
Also known as grinding,
roughing, or rough grinding. These finishes are course in nature
and usually are a preliminary finish applied before
manufacturing. An example of this would be grinding gates off
castings, deburring, or removing excess weld material. It is
course in appearance and is accomplished by using a 36-100 grit
abrasive. When the finish is specified as a #3, the material is
polished to a uniform 60-80 grit.
#4
Architectural Finish:
Also known as brushed,
directional, or satin finish. A #4 architectural finish is
characterized by fine polishing grit lines that are uniform and
directional in appearance. It is produced by polishing the metal
with a 120-180 grit belt or wheel finish and then softened with
an 80-120 grit greaseless compound, or a medium non-woven
abrasive belt or pad.
#4 Dairy or
Sanitary Finish:
This finish is commonly
used for the medical and food industry, and almost exclusively
used on stainless steel. This finish is much finer than a #4
architectural finish. Great care should be taken in removing any
surface defects in the metal, such as pits, that could allow
unwanted bacteria to grow. A #4 Dairy or Sanitary Finish is
produced by polishing 180-240 grit belt or wheel, softened with
a 120-240 grit greaseless compound, or fine non-woven abrasive
bely or pad.
#6 Finish:
Also known as a fine satin
finish. This finish is achieved by polishing with a 220-230
greaseless compound, or very fine non-woven abrasive belt or
pad. Polish lines should be soft and less reflective than #4
architectural finish.
#7 Finish:
A #7 finish is achieved by
polishing with a 280-320 grit belt or wheel, and sisal buffing
with a cut and color compound. This is a semi-bright finish that
will still have some polishing lines, however, they will be very
dull. Carbon steel, and iron are commonly polished to a #7
finish before chrome plating occurs. A #7 finish can be
brightened by color buffing with a coloring compound, and a
cotton buff. This is an excellent way to keep polishing costs
down when a part needs to be shiny, but not flawless.
#8 Finish:
Also known as a mirror
finish, this finish is achieved by using at least a 320 grit
belt or wheel finish. Extra care should be taken in making sure
all surface defects are removed. The part is sisal buffed, and
then color buffed to achieve a mirror finish. The quality of the
finish depends greatly on the quality of the metal being
polished. Unfortunately, some alloys of steel and aluminum
cannot be brought to a mirror finish. Castings that have slag or
pits will be extremely difficult, if not impossible to polish to
a #8 finish.
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