Galvanized or Coated spring, what
There is no such thing as a coated spring.
The term is often used in reference to
coating with paint. A standard oil tempered
spring is coated with a poor quality paint
product. Lasting a short time. Galvanizing by
definition means a metallurgical reaction
between zinc and iron to create a bond
between the zinc and the steel of
approximately 3600 psi. There is no such
reaction when paints are applied and the
bond strength is only a painting system.
How does galvanizing
protect springs from corrosion?
Zinc metal used in the galvanizing
process provides an impervious barrier
between the steel substrate and corrosive
elements in the atmosphere. It does not
allow moisture and corrosive chlorides and
sulfides to attack the steel. Zinc is more
importantly anodic to steel -meaning it
will corrode before the steel, until the
zinc is entirely consumed.
How does the cost of hot-dip
galvanizing compare to other corrosion
protection systems, such as paints or
When compared with paint systems or
coated, hot-dip galvanizing after
fabrication has comparable initial
application costs and, almost always,
adds Longer life-cycle. In fact, the higher
life-cycle of a hot-dip galvanized spring
makes galvanizing the smart choice for today
How long can I expect my
galvanized steel spring to last in service?
Hot-dip galvanized steel resists
corrosion in numerous environments extremely
well. It is not uncommon for galvanized
steel springs to last more than 70 years
under certain conditions.
Does the galvanized coating of
zinc resist abrasion?
The three intermetallic layers that
form during the galvanizing process are all
harder than the substrate steel and have
excellent abrasion resistance.
What are the specifications
governing hot-dip galvanized steel?
Structural steel (plate, wide-flange beams,
angles, channels, pipe, tubing) are galvanized to ASTM A
123/A 123M. Fasteners and small parts that fit into a
centrifuging basket are galvanized to ASTM A 153/A 153M.
Reinforcing steel is galvanized to ASTM A 767/A 767M
Isn't galvanizing more expensive
than coated springs?
Depending on the product mix and
condition of the steel surface, galvanizing
is often less expensive on an initial
cost basis. However, as with any purchase,
lifetime costs should be considered when
making a project decision on the corrosion
Is the Galvanized coating's
thickness consistent over the entire piece?
Coating thickness depends on the
thickness, roughness, chemistry, and design
of the steel being galvanized. Any or all of
these factors could produce galvanized
coatings of non-uniform thickness. Members
of the American Galvanizers Association
galvanize all torsion springs to ASTM
standards, which define minimum average
coating thickness grades for various
Can I specify how much
Galvanized zinc to put on the springs?
No, the steel chemistry and surface
condition are the primary determinants of
springs that are galvanized zinc coated.
Sometimes, the galvanized
coating is shinier in some places than
others. Why is that?
The galvanized coating appearance
may either be bright and shiny resulting
from the presence of an outer layer of pure
zinc, or duller, matte gray as the result of
the coating's inter-metallic layers being
exposed. Performance is not affected.