What is Electromarking?
Electromarking is chemical marking or etching with the use of
electrical current. Using an amperage power unit and a stencil
of the desired marking, a solution referred to as an electrolyte
is applied, which allows the electrical current to pass through
and onto the metal.
Electromarking produces a sharp, attractive design or impression.
The aircraft and defense industries prefer it because it does
not cause distortion or sharp indentations in the metal. Also,
manufacturers who produce quality cutlery, feeler gages, saw
blades, and carbides like Electromarking for its clean, clear
impression. In general, Electromarking is most applicable where
hardened, or thin, or already assembled parts must be marked
permanently with no distortion.
One can perform Electromarking
on almost any bare metal (except painted or anodized surfaces).
It isnt necessary to clean the surface before marking with
any chemicals, but a lightly oiled surface may improve the mark.
Many plated surfaces can also be Electromarked.
Electromarking is recognized
as the best way to permanently mark conductive metal surfaces.
It does not cause distortion, sharp indentation, stress, burrs
or strain. The mark is permanent because metal is etched away
from the surface through the design stencil.
Electromarking can produce an
etch ranging from less than .0001" to as deep as 0.010",
through the use of AC or DC current. AC current makes a shallow
etch from .0001" to .0002" in depth, depending on the
length of time the stencil and the solution are in contact with
the metal. The resulting etch is dark or contrasts with the surrounding
metal. The degree of darkness depends on many things; however,
the base metal is the most important.
For example, some stainless
steels give only a brown mark, whereas monel metal gives a jet
black mark. With AC, metal is etched away during half of the
cycle and an oxide is deposited in the etch during the other
half of the cycle. This oxide deposit will withstand corrosive
action, as has been demonstrated by its capability to stand up
under extensive salt spray tests over long periods of time. DC
current provides a deep etch from .0001" to.010" in
depth. This leaves a clear or white etch on most metals. With
DC, metal is etched away during the complete cycle. The deep
etch cannot be removed without removing the base metal to the
depth of the etch.
Why Use Electromarking?
Electromarking is simple, fast, safe and economical. The electrolyte
solution is nearly neutral on the ph scale and therefore will
not damage skin, clothing or the environment.
Hardened, thin or delicate,
already assembled parts and even carbides can be marked easily
and permanently without distortion. Therefore, electromarks will
not peel off, rub off, fall off or become lost. All conductive
metal surfaces, including plated surfaces and the majority of
other supplemental coatings can be marked. Parts can be marked
for stock identification in the field. Additionally, parts can
be marked immediately after production or assembly, or can be
stored without a mark and then quickly marked prior to shipment.
This is beneficial where the same part may require a different
identification for different customers.
Who Uses Electromarking?
Dunnrite Propellers have been Electromarking stainless steel
propellers for many years now. A wide range of manufacturers
use Electromarking. Manufacturers who produce fine cutlery, feeler
gauges, saw blades and other components all prefer this method
of marking. Electromarking is used extensively by the aerospace,
aircraft and automobile industries.