AISC Structural Shap..

Report
Steel Construction Manual
American Institute of Steel Construction
Thirteenth Edition
Part 1
Dimensions and Properties
Wide-flange (W) Shapes
Most widely used section
Two flanges held apart by a web
Essentially parallel inner and outer flange
surfaces
Section designation
W 24 x 55
Weight in pounds/per foot
Nominal depth in full inches
Nominal depths from 4-inch to 44 inch
Weights available from 9 lb/ft to 800 lb/ft
Wide-flange (W) Shapes
W 14 x 730
Actual depth is
22.4 inches
W 14 x 90
Actual depth is
14 inches
All shapes from W14 x 90 to W 14 x 730
have flat (T) part of web of 10 inches.
All these shapes can be stacked on each
other
Major axis
Flange
Web
Weak axis
Designation
Actual depth
Cross-sectional
area
Flange
Properties
WebThickness
End of fillet
transition between
web and flange
Flat portion of
web
Spacing between rows
of bolts in flange
Moment of Inertia (I), elastic section modulus (S), radius
of gyration (r), plastic section modulus (Z) for strong and
weak axes
Weight per foot
Flange and web stability
parameters
M-Shapes
Not classified in ASTM 6 as W-, S- or HP- shapes
Same properties (A, d, tw, bf, etc) as W- shapes
Can have sloped inside flange or other features
American Standard (S) Shapes
16-2/3% slope on inner flange surface
Relatively narrow flanges and thicker webs when
compared to W shapes
Section designation
S24x121
Weight per foot
Nominal depth
Use is less common because of lower moment of inertia,
tapered flanges and low lateral stiffness
Narrow flange
Note: slope on inside of flange
Same properties as for W shapes
Channels
Nominal depth is same as actual depth
Section designation
C15x50
Weight in pounds per foot
Actual depth
MC – Miscellaneous channel – Other than 2 on 12 slope on
inner flange
Property for design
Actual depth
Property for
detailing
Angles
For a single angle major axes do not correspond to
x and y axes
Section designation
Short leg length
L6x4x3/4
Thickness of both legs
Long leg length
Equal leg and unequal leg angles available
Angles are best used in pairs as LLBB (Long-legback-to-back) or SLBB (Short-leg-back-to-back).
Location of elastic centroid
Location of plastic centroid
Designation
X axis properties
Minor (weak) axis for a single angle
Y axis properties
Tees
WT -, MT- and ST- are obtained by shearing or thermalcut from parent shape of W, M and S respectively
Two WT 22 x 131 can be made by cutting a W 44 x 262
Nominal depths and weights of a WT is exactly half
of the parent shape
Off-center cuts can be done but properties not listed in
Manual
Used for top and bottom chords of trusses and
diagonal bracing in buildings
Stem, not web
Hollow Structural Shapes
Rectangular, Square or Round HSS
Welded or Seamless
Welded HSS made by welding sheet steel
Seamless made by extrusion of solid round bars
Outside longer dimension
HSS 10 x 4 x 3/8
Wall thickness
Outside shorter dimension
Section Designation
Outside Longer
Dimension
Strong axis structural properties
Actual Wall Thickness
Outside Shorter
Dimension
Design Wall Thickness = 0.93 x Actual Wall
Thickness
Weak axis structural properties
Equal outside dimensions
Structural properties for
strong and weak axes
Nominal versus
design thickness
Diameter over design
thickness
Nominal wall
thickness
Standard, x-strong and xx-strong designations
Double Angles
2L6x4x3/4
Major axes are now x and y
X axis properties may be obtained from x axis
properties of single angle
Y axis properties depend on separation between backs
angles and whether LLBB or SLBB
Long legs back-to-back
Short legs back-to-back
Radius of gyration for compression members
Separation due
to gusset plates
Double Channels
Designated as 2C or 2MC
2C15x50
Y axis properties depend on back-to-back separation
X axis properties can be obtained from x axis
properties of single channel
Y axis properties depend on back-to-back
distance (gusset plate thicknesses) between
individual channels
Suitable for Crane Girders
Channel
W shape
Weight
Moment of
Inertia, Ixx
Nominal wall
thickness
Preferred Specification
Limited availability
Steel
Types
Plates > 8 inch width
Bars < 8 inch width
Thickness in inches

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