Aisc Basics.Pdf

W-Shapes | ASTM A992, Fy = 50 ksi, Fu = 65 ksi
S-Shapes | ASTM A36, Fy = 36 ksi, Fu = 58 ksi
C- and MC-Shapes | ASTM A36, Fy = 36 ksi, Fu = 58 ksi
CONDITION

ASD

Bending

Strong
Axis

Lb ≤ Lp
L p < Lb ≤ Lr
Lb = Lr

0.9 Fy Ag ≤ 0.75 Fu Ae

For Ae, see Equation D3-1.

0.66 Fy S x

0.99 Fy S x

See Note 1.
L p = 300 ry Fy

Use linear interpolation between Lp and Lr.

Klr ≤ 800

Fy

Kl r > 800

Fy

0.63Fy S x

1.35Fy S y

0.4 Fy Aw

Shear (in strong axis)

0.42 Fy S x

0.9 Fy S y

Weak Axis

Compression

RELATED INFO

0.6 Fy Ag ≤ 0.5 Fu Ae

Tension

LRFD

0.6 Fy Aw

See Note 2.

0.6 Fy Ag × 0.658P

0.9 Fy Ag × 0.658P

P = Fy ( Kl r ) 286, 000

150, 000 Ag

( Kl r )

2

226, 000 Ag

( Kl r )

Lr and strengthswhen Lb > Lr
are given in the AISC Manual.

2

2

See Note 3.

Notes:
1. Multiply equations given for Lb ≤ Lp by value in parentheses for W14×90 (0.97), W12×65 (0.98), and W6×15 (0.95).
2. Multiply equations given by 0.9 for W44×230, W40×149, W36×135, W33×118, W30×90, W24×55, W16×26, W12×14 and all Cand MC-shapes. In weak axis, equations given can be adapted by using Aw = 1.8bftf.
3. Notapplicable to slender shapes. For slender shapes, use QFy in place of Fy, where Q = QsQa from Section E7. For C- and MCshapes, also check Section E4.
Copyright © 2005
Based upon simplifying assumptions and arbitrary
limitations. Direct use of the 2005 AISC Specification
may be less constrained and less conservative.

Basic Design Values 1

American Institute of Steel Construction, Inc.One East Wacker Drive, Suite 700
Chicago, IL 60601
www.aisc.org
structural steel: the material of choice

Bolts | ASTM A325, Fu = 120 ksi or ASTM A490, Fu = 150 ksi
Welds | FEXX = 70 ksi
Connected Parts

Copyright © 2005 by AISC

ASD

LRFD

RELATED INFO

Tension

0.38 Fu Ab

0.56 Fu Ab

--

Shear (N bolts, per shear plane)

0.2 Fu Ab

0.3Fu Ab

Multiply by 1.25 for Xbolts.

Slip Resistance (Class A, STD holes)

0.14 Fu Ab

0.21Fu Ab

Per slip plane. See Note 1.

0.6 Fu Lc t ≤ 1.2 Fu db t

0.9 Fu Lc t ≤ 1.8 Fu db t

See Note 2.

Shear (all welds except CJP)

0.3FEXX Aw

0.45 FEXX Aw

See Note 3.

Tension

0.32 FEXX Aw

0.48 FEXX Aw

See Section J2.1a.

0.48 FEXX Aw ≤ 0.6 Fy ABM

0.72 FEXX Aw ≤ 0.9 Fy ABM

Joint not finishedto bear.

Bolts

CONDITION

Welds

Bearing

PJP Groove Welds

Compression

Strength equal to base metal.

Connected Parts

CJP Groove Welds

--

Tension

0.6 Fy Ag ≤ 0.5 Fu Ae

0.9 Fy Ag ≤ 0.75 Fu Ae

For Ae, see Equation D3-1.

Shear

0.4 Fy Ag ≤ 0.3Fu An

0.6 Fy Ag ≤ 0.45 Fu An

--

0.3Fu Anv + 0.5U bs Fu Ant

0.45Fu Anv + 0.75U bs Fu Ant

See Note 4.0.6 Fy A

0.9 Fy A

Block Shear
Kl r ≤ 25

Compression

Kl r > 25

Same as for W-shapes with Ag = A.

--

Notes:
1. Slip checked as a serviceability limit state using ASD load combinations for ASD, LRFD load combinations for LRFD. For
Class B surfaces, multiply by 1.43. For OVS or SSL holes, multiply by 0.85. For LSL holes, multiply by 0.7.
2. For LSL holes parallel to thedirection of load, multiply by 0.83.
3. For fillet welds, multiply by 1.5 for transverse loading (90-degree load angle). For other load angles, see Section J2.
4. For calculation purposes, FuAnv cannot exceed FyAgv. Ubs = 1 for a uniform tension stress; 0.5 for non-uniform tension stress.

HSS | ASTM A500 grade B, Rectangular Fy = 46 ksi, Fu = 58 ksi , Round Fy = 42 ksi, Fu = 58 ksi
Pipe | ASTMA53 grade B, Fy = 35 ksi, Fu = 60 ksi
CONDITION

ASD

LRFD

RELATED INFO

0.6 Fy Ag ≤ 0.5 Fu Ae

0.9 Fy Ag ≤ 0.75 Fu Ae

For Ae, see Equation D3-1.

Rectangular HSS

0.66 Fy S

0.99 Fy S

See Note 1.

Round HSS, Pipe

0.78Fy S

1.17 Fy S

See Note 2.

Rectangular HSS

0.36 Fy Aw

0.54 Fy Aw

See Note 3.

Round HSS, Pipe

0.18 Fy Ag

0.27 Fy Ag

See...