Metal Engraving
Metal engraving, also known as metal
etching, milling or machining, is the production of a depressed design on a
metal plate. These grooves and patterns are used for a variety of purposes,
from jewelry and gunsmith decoration to industrial stencils and circuit boards.
For decorative etching, the surfaces are sometimes smoked so that the lines
will be more visible. Etching is used to create metal industrial parts that
require many small grooves or holes, or as a decorative finish on many metals.
Metal etching can also help a metal to meet weight demands by dissolving an
appropriate layer of the surface. There are now several different methods to
mill metal, each with different results.
Mechanical milling employs the use of a lathe or milling machine with rotogravure
tips. Hobbyists and artists often engrave by hand with steel pointed tools. Chemical
milling, or acid
etching, uses a process of masking and corrosive chemical exposure to create
grooves, images, and pocked surfaces, and photo
etching, similar to chemical milling, uses photographic technology to create
a light-developed pattern which is then etched chemically. Electro discharge
machining, or EDM, is similar to both chemical and photo etching, except that
instead of exposing metal etching surfaces to chemicals, they are exposed to
streams of corrosive electromagnetic discharge. Laser etching is another type
of engraving which is used to create very fine, clean lines in metal surfaces.
After the metal has been etched, pock marks or imperfections may be smoothed
or burnished away.
A broad range of metals can be used during the acid-based processes, such as
stainless steel, copper, brass, nickel and silver alloy. Other metals can be
etched using gas or electric-based processes. If a metal piece is in need of
fine grooves, laser etching is often used. Abrasive etching with high-compression
air is another option. In this process, abrasives such as aluminum oxide or
sand are sometimes blasted in place of laser technology when isolated areas
are being worked. Photochemical etching, which is the most common etching method,
is a low-cost process that provides high quality, fast turnaround and precision
accuracy unavailable in other etching processes. This process also allows flexibility
in the design of parts, as changes can be made quickly, simply and cost-effectively.
Metals are etched by many industries for a variety of purposes. The medical
field uses stents, cathodes and implants. Brake rotors and fuel cell plates
are made for the automotive industry. The sign and plaque industry heavily
relies on the use of etching services, and jewelry manufacturers use metal
etching to create fine lines for intricate details. Photochemical etching produces
business cards, logo name plates, panel covers and promotional items for the
commercial sector. Metal etching services also create longer lasting stencils
for the woodworking and art fields, printed circuit boards for the aerospace
and electronics industries, and engraved or reduced missile skin panels and
jet frames for defense. Book publishers, illustrators and artists use metal
engraved plates to produce multiple pressed images, although engraved illustrations
are beginning to fall out of use. Many hobbyists and artists continue to use
hand engraving, which yields a less precise but more organic result.