Documentos

steelwise

Your connection to
ideas + answers

Are You Properly Specifying Materials?
By martin anderson and charles j. carter, s.e., p.e.

Keeping tabs on available ASTM Specifications for each structural shape
will help you make the right choices when designing your projects.
ThE MATERIALS AND PRODUCTS USED IN bUILDINg
DESIgN and construction are almost universally designated byreference to an appropriate ASTM specification. This simplifies the
design and construction process because you can define all the characteristics of a specified product. However, with dozens of ASTM
specifications applicable in steel building construction alone, it can
be a challenge to keep the standard designations used in contract
documents current.
This article provides a summary of thecommon ASTM specifications used in steel building design and construction, including structural shapes, plate products, fastening products, and
other products. This information is based upon similar and more
extensive information in the 13th Edition AISC Steel Construction
Manual. The reader may also find it convenient to use the recently
revised AISC publication Selected ASTM Standards forStructural
Steel Fabrication 2008, which is a compilation of more than 60 steelrelated ASTM standards. Both of these publications are available
for purchase online at www.aisc.org/bookstore.
STRUCTURAL ShAPES
See the summary in Table 2-1.
W-Shapes
The preferred material specification for W-shapes is ASTM
A992 (Fy = 50 ksi, Fu = 65 ksi). The availability of W-shapes
in grades other than ASTM A992should be confirmed prior to
their specification. W-shapes with higher yield and tensile strength
can be obtained by specifying ASTM A572 Grade 60 or 65, or
ASTM A913 Grades 60, 65, or 70. W-shapes with atmospheric corrosion resistance (weathering) characteristics can be obtained by
specifying ASTM A588 or ASTM A242 Grade 42, 46, or 50. Other
material specifications applicable to W-shapesinclude ASTM A36,
ASTM A529 Grade 50 and 55, ASTM A572 Grade 42 and 50, and
ASTM A913 Grade 50.
M-Shapes and S-Shapes
The preferred material specification for M- and S-shapes is in
transition. ASTM A36 (Fy = 36 ksi, Fu = 58 ksi) has been traditional,
but at least one steel producer now sells these shapes in ASTM
A572 Grade 50 (Fy = 50 ksi, Fu = 65 ksi) for a lower price than
ASTM A36. Duringthis transition, we suggest you ask a fabricator what grade is most common when you use these shapes. The
availability of M-shapes in other grades should be confirmed prior
to their specification. M-shapes with atmospheric corrosion resistance (weathering) can be obtained by specifying ASTM A588 or
ASTM A242 Grade 50. Other material specifications applicable to

M- and S-shapes include ASTMA572 Grades 42, 55, 60, and 65,
ASTM A529 Grades 50 and 55, ASTM A913 Grades 50, 60, 65, or
70, and ASTM A992.
Channels
The preceding comments for M- and S-shapes apply equally
to channels.
hP-Shapes
The preferred material specification for HP shapes is ASTM
A572 Grade 50 (Fy = 50 ksi, Fu = 65 ksi); the availability of other
grades should be confirmed prior to specification. HP-shapeswith
atmospheric corrosion resistance (weathering) can be obtained by
specifying ASTM A588 or ASTM A242 Grades 46 or 50. Other
material specifications applicable to HP-shapes include ASTM
A36, ASTM A529 Grades 50 or 55, ASTM A572 Grades 42, 55, 60,
and 65, ASTM A913 Grades 50, 60, 65, and 70, and ASTM A992.
Angles
The preferred material specification for angles is ASTM A36
(Fy = 36 ksi, Fu =58 ksi). The availability of angles in grades other
than ASTM A36 should be confirmed prior to their specification.
Angles with higher yield and tensile strength can be obtained by
specifying ASTM A572 Grade 42, 50, 55, 60, or 65, ASTM A529
Grades 50 or 55, ASTM A913 Grades 50, 60, 65, or 70, and ASTM
A992. Angles with atmospheric corrosion resistance (weathering)

Martin Anderson is...