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Commercial Steel (CS)
This
designation is for the basic product, useful for many applications
requiring the strength of steel combined with the workability
needed for bending and moderate forming. It provides the strength
and formability levels that most users need for general purpose
applications.
CS sheet is subject to a phenomenon called aging; therefore, if
the sheet must be free from strain lines (stretcher strains,
flutes, etc.) after fabrication, it should be roller leveled just
before the forming operation.
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Forming Steel (FS)
 The primary difference between FS and CS sheet is that
FS sheet is processed to be more formable, i.e., easier to bend,
etc. FS sheet is slightly more formable than CS and is typically
used for applications where breakage (splitting) might be
encountered when CS sheet is not quite formable enough to make a
part. Often, FS is selected to allow easier bending with less
springback. FS sheet is produced from specially selected steels,
processed for improved and more uniform formability properties.
FS sheet is subject to the same aging phenomenon as CS sheet;
therefore, to avoid strain lines, FS sheet should be roller leveled
just before the forming operation.
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Deep
Drawing Steel (DDS)
DDS
sheet is produced from aluminum-killed steel employing special
steelmaking practices. It can be produced using restricted
low-carbon steels or interstitial-free steels depending on the
application requirement and the producing facility. It has forming
characteristics superior to CS and FS sheet. These characteristics
make it excellent for applications involving deep drawing or
combinations of drawing and stretching.
DDS sheet is non-aging. DDS sheet is recommended for use when
improved drawability is required and the effects of aging (slight
hardening, loss of ductility, and strain lines) are undesirable or
roller-leveling equipment is not available.
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Extra Deep Drawing Steel (EDDS)
Coated
sheet of this quality is characterized by excellent uniformity and
exceptional formability. EDDS Sheet is produced from vacuum
degassed steel to achieve a very low carbon content. Also,
stabilizing elements such as titanium and niobium (columbium) are
added during steel production to combine with the residual
amounts of carbon and nitrogen remaining in the degassed steel to
make it "interstitial-free". The final product is excellent for
deep drawn parts in that the sheet exhibits a high resistance to
thinning during drawing.
EDDS Sheet is non-aging. Thus, coil breaks, strain lines and
fluting during fabrication are not encountered.
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Structural Steel (SS)
 SS
sheet is recommended for applications in which specific mechanical
properties are required for strength in a finished part, usually in
load-bearing structures. Orders for SS usually require that minimum
yield and tensile strengths be met by the steel producer. The
required strength level is achieved through the use of carbon,
manganese, phosphorus, and/or nitrogen additions during
steelmaking. When specifying a SS grade, the user should carefully
consider the compatibility of the specified properties with forming
requirements. In general, steels produced to meet
increasing yield strength levels have a corresponding decrease in
ductility or formability.
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High
Strength Low Alloy Steel (HSLAS)
HSLAS sheet is defined as having a specified
minimum yield strengths of 35 ksi or higher. HSLAS steels are
produced to meet minimum yield and/or tensile strength levels.
Often, these steels are intended for applications that require more
ductility (% elongation) than Structural Steels. For this reason,
they are generally produced using micro-alloying technology wherein
additions of elements such as titanium, niobium (columbium) and
vanadium are added during steelmaking. The most common types of
HSLAS sheet exhibit yield strengths in the range of 35 to 70 ksi.
Typically, the tensile strength is 10 to 15 ksi higher than the
yield strength. Higher strength steels are available, but they
often exhibit relatively low formability.
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Coating Thickness
Similarly, the zinc coating weight categories are the same as those
applied to galvanized sheet. For ACRYZINC® sheet, therefore, it
is necessary to specify the zinc coating weight, i.e., G90, etc.
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Coating Thickness -
English Units
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ASTM A653
Coating Designation1)
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Minimum
Coating Weight
oz/sq ft
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Triple Spot Average
Total Both Sides (2)
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Single Spot
Test
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One Side
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Total
Both Sides |
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G210
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2.10
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0.72
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1.80 |
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G185
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1.85
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0.64
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1.60 |
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G165
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1.65
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0.56
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1.40 |
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G140
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1.40
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0.48
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1.20 |
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G115
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1.15
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0.40
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1.00 |
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G90
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0.90
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0.32
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0.80 |
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G60
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0.60
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0.20
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0.50 |
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G40
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0.40
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0.12
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0.30 |
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G30
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0.30
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0.10
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0.25 |
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Coating Thickness -
English Units
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Coating
Designation
(1,3)
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Minimum
Coating Weight
g/sq m (4)
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G20/20
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20
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G40/40
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40
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G50/50
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50
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G60/60
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60
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G70/70
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70
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G90/90
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90
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G98/98
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98
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1. The coating designation number
is the term by which this product is ordered.
2. The weight of coating in oz. per sq. ft.
refers to the total coating on both surfaces. The triple spot
average encompasses an edge-center-edge sampling to determine
adequate coverage across the sheet width. Typically, about half
this coating is on each side.
3. Ordered coating weight is specified on a
per-side basis, e.g., 50/50 requires each surface to have a minimum
coating weight of 50 g/m2.
4. To convert coating weight from oz/sq ft to
g/sq m the following factor can be used: g/sq m = oz/sq ft x
305.15.
Note that, although a precise conversion
between ASTM A653 "G" categories (G30, G60, etc.) and the metric
categories (20/20, 40/40, etc.) cannot be made, a G60 coating
category (ASTM A653) is approximately equal to a 90/90 coating
category (metric).
Surface Finish
The surface finish of ACRYZINC® sheet is basically
unchanged from the finish normally observed on hot-dip galvanized
sheet. That is, the clear acrylic coating does not hide the
spangled finish ranging from Regular Spangle to Minimum Spangle
(small but visible grain pattern) depending on the normal practices
used on the hot-dip coating line. The thin acrylic film may give
the surface a somewhat satiny appearance especially when it is
observed at an oblique angle, but the spangled finish of the
galvanized coating is clearly visible.
Surface Treatment
The acrylic coating on U.S. Steel ACRYZINC® sheet does
not require the use of any other surface treatment. The acrylic
coating offers the combined benefit of high resistance to storage
staining and the lubricating benefits of oil. The product is not
intended to be oiled. The absence of a rust-inhibiting oil benefits
worker safety.
The product is only available with no additional surface
treatments.
ACRYZINC® is a registered trademark of United
States Steel.
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