What is A992 Steel Properties used for in structural engineering?

A992 Steel Properties provides values required for steel design calculations including capacity checks, connection design, and detailing. It is referenced in structural design codes and used by practicing engineers during the design of buildings, bridges, and industrial structures.

Can I use these reference values directly in my design?

Yes, provided the values match your governing code edition and project specifications. Always cross-reference against the primary source (code document, manufacturer data, or published standard). The information on this page is for educational use — final verification by a licensed engineer is required.

How often are these reference values updated?

Reference content is maintained to align with current code editions. When a new edition of AISC 360, AS 4100, EN 1993, or CSA S16 is published, values are reviewed and updated. Check the last-modified date at the bottom of the page and verify against the current edition for your jurisdiction.

A992 Steel Properties — Yield Strength, Tensile Strength & Applications

ASTM A992 is the standard structural steel for all hot-rolled W-shape, M-shape, and S-shape sections produced in the United States. With a yield strength of 50 ksi (345 MPa) and tensile strength of 65 ksi (450 MPa), A992 provides superior strength and ductility compared to the legacy A36 grade. This page covers A992 mechanical properties, the Fy/Fu ratio requirement, and why A992 became the default W-shape grade.

Quick access: A36 Steel → | A572 Grade 50 → | Beam Calculator → | Section Properties →

A992 Steel Mechanical Properties

Yield and Tensile Strength

Property	Imperial	Metric	AISC 360 Symbol
Yield strength (Fy)	50 ksi	345 MPa	Fy
Tensile strength (Fu)	65 ksi	450 MPa	Fu
Fy/Fu ratio	0.85 max	0.85 max	—
Modulus of elasticity (E)	29,000 ksi	200,000 MPa	E
Shear modulus (G)	11,200 ksi	77,200 MPa	G
Poisson's ratio	0.30	0.30	—
Density	490 lb/ft³	7,850 kg/m³	—

Elongation Requirements

Specimen	Minimum Elongation
8-inch gauge length	18%
2-inch gauge length	21%

The Fy/Fu Ratio — Why It Matters

The key difference between A992 and A572 Grade 50 is the Fy/Fu ratio limit. A992 requires Fy/Fu ≤ 0.85, ensuring:

Ductile behavior — The steel yields well before fracture, providing warning before failure
Reliable plastic hinge formation — Critical for moment frame design in seismic regions
Consistent material properties — Tighter control reduces variability in connection design

This ratio requirement was introduced after the 1994 Northridge earthquake, which revealed connection failures in moment frames using A36 and A572 steel.

A992 Chemical Composition

Element	Maximum (%)	Typical (%)
Carbon (C)	0.23	0.18
Manganese (Mn)	1.35	1.00
Phosphorus (P)	0.035	0.02
Sulfur (S)	0.04	0.025
Silicon (Si)	0.40	0.25
Copper (Cu)	0.60	0.30
Nickel (Ni)	0.45	0.15
Chromium (Cr)	0.35	0.10
Vanadium (V)	0.11	0.03
Columbium (Nb)	0.05	0.02

Carbon Equivalent (CE)

A992 has a maximum CE of 0.45 (IIW formula) for plates and shapes up to 4 inches thick. This ensures good weldability without excessive preheat.

CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

Why A992 Replaced A36 for W-Shapes

Historical Context

Prior to 1998, most W-shapes in the US were produced to ASTM A36 (Fy=36 ksi). The shift to A992 was driven by:

Northridge Earthquake (1994) — Brittle fractures in A36 moment frame connections exposed the lack of ductility controls
Research findings — Studies showed A36 steel had highly variable yield-to-tensile ratios, sometimes exceeding 0.85
Higher strength demand — A992's 50 ksi yield provides 39% more capacity than A36 for the same section

Benefits of A992 over A36

Attribute	A36	A992	Improvement
Yield strength	36 ksi	50 ksi	+39%
Tensile strength	58 ksi	65 ksi	+12%
Fy/Fu ratio	No limit	0.85 max	Ductility guarantee
Charpy impact	Not required	Supplementary available	Fracture toughness
Section availability	Limited new production	All W/M/S shapes	Better supply

Current Status

Since 1998, all major US mills produce W-shapes to A992 exclusively. A36 W-shapes are no longer available for new orders. Existing A36 W-shapes in structures remain safe but should be analyzed with Fy=36 ksi, not Fy=50 ksi.

Weldability

A992 has good weldability, comparable to A572 Grade 50.

Preheat Requirements

Thickness	Preheat (AWS D1.1)
Up to 3/4 in. (19 mm)	Not required (above 32°F)
3/4 to 1-1/2 in. (19-38 mm)	50°F (10°C) minimum
1-1/2 to 2-1/2 in. (38-64 mm)	150°F (65°C) minimum
Over 2-1/2 in. (64 mm)	200°F (93°C) minimum

Electrode Selection

Use matching-strength electrodes:

SMAW: E7018 (70 ksi tensile matches A992's 65 ksi Fu)
FCAW: E71T-1
GMAW: ER70S-6
SAW: F7A2-EM12K

A992 vs A572 Grade 50

These grades have identical Fy (50 ksi) and Fu (65 ksi), but differ in key ways:

Attribute	A992	A572 Grade 50
Fy/Fu ratio	0.85 max	No requirement
Product forms	W-shapes, M-shapes, S-shapes	Plates, bars, shapes
Charpy testing	Supplementary available	Supplementary available
Mill certification	Tighter controls	Standard controls
Cost	Same	Same

Rule of thumb: Use A992 for all W-shape members. Use A572 Grade 50 for plates, bars, and built-up sections.

AISC 360 Design with A992

Available Strength in Flexure

For compact W-shapes with full lateral support:

Mn = Mp = Fy × Zx = 50Zx (kip-in)

Worked Example — W16x31 Beam in Flexure

Problem: Check the available moment strength of a W16x31 (Zx = 54.0 in³) in A992 steel with full lateral support.

Solution:

Mn = Mp = Fy × Zx = 50 × 54.0 = 2,700 kip-in = 225 kip-ft
LRFD: phiMn = 0.90 × 225 = 202.5 kip-ft
ASD: Mn/Omega = 225/1.67 = 134.7 kip-ft

Available Strength in Compression

For a compact W-shape (no local buckling):

Pn = Fy × Ag = 50Ag (short columns)

For long columns, use AISC column curves with KL/r.

Available Strength in Shear

For unstiffened W-shape webs:

Vn = 0.6Fy × Aw × Cv

Where Aw = d × tw and Cv depends on h/tw ratio.

Worked Example — W14x90 Column in Compression

Problem: Check a W14x90 A992 column with KL=18 ft (strong axis) and KL=9 ft (weak axis).

Given:

W14x90: Ag = 26.5 in², rx = 6.14 in, ry = 3.70 in
KLx = 18 ft = 216 in, KLy = 9 ft = 108 in

Solution:

KLx/rx = 216/6.14 = 35.2
KLy/ry = 108/3.70 = 29.2
Governs: KL/r = 35.2 (strong axis)
Fe = π²E/(KL/r)² = π²(29,000)/35.2² = 230.8 ksi
Fy/Fe = 50/230.8 = 0.217 < 2.25
Fcr = 0.658^0.217 × 50 = 0.909 × 50 = 45.5 ksi
Pn = Fcr × Ag = 45.5 × 26.5 = 1,205 kips
LRFD: phiPn = 0.90 × 1,205 = 1,085 kips
ASD: Pn/Omega = 1,205/1.67 = 722 kips

A992 for Moment Frames

A992 is the required grade for special moment frames (SMF) and intermediate moment frames (IMF) in seismic design.

Why A992 for Seismic

Fy/Fu ratio — The 0.85 max limit ensures plastic hinges form before fracture
Ductility — Controlled yielding provides energy dissipation capacity
Connection reliability — Consistent properties reduce connection failures
Code requirement — AISC 341 requires A992 for all moment frame W-shapes

Prequalified Connections

AISC 358 prequalified moment connections for A992 include:

Reduced Beam Section (RBS)
Bolted Unstiffened End Plate (BUEP)
Bolted Stiffened End Plate (BSEP)
Welded Unreinforced Flange-Welded Web (WUF-W)

All prequalified connections assume A992 material properties.

Calculator

Design steel members with A992 steel using our free calculators:

Beam Capacity Calculator → — Check flexural strength for any A992 W-shape
Column Buckling Calculator → — AISC compression capacity with KL/r
Bolted Connection Calculator → — Shear tab and end plate design
Section Properties → — Full AISC section database

FAQ

Q: What is the yield strength of A992 steel? A: ASTM A992 steel has a minimum yield strength of 50 ksi (345 MPa) and a minimum tensile strength of 65 ksi (450 MPa). The Fy/Fu ratio must not exceed 0.85.

Q: Why did A992 replace A36 for W-shapes? A: A992 replaced A36 because it provides 39% higher yield strength (50 ksi vs 36 ksi), has a mandatory Fy/Fu ratio limit (0.85 max) ensuring ductile behavior, and costs the same. The shift was driven by connection failures in the 1994 Northridge earthquake.

Q: Can I use A572 Grade 50 instead of A992? A: For W-shapes, no — mills produce all W-shapes to A992. For plates and bars, A572 Grade 50 is the correct specification. Both have identical Fy (50 ksi) and Fu (65 ksi), but A992 has the additional Fy/Fu ratio requirement.

Q: Is A992 steel weldable? A: Yes, A992 has good weldability. Use E7018 low-hydrogen electrodes. Preheat is generally not required for thicknesses up to 3/4 inch (19 mm). For thicker sections, follow AWS D1.1 preheat tables.

Q: What is the Fy/Fu ratio and why does it matter? A: The Fy/Fu ratio is the yield strength divided by the tensile strength. A992 requires this ratio to be 0.85 or less. This ensures the steel yields (deforms) well before it fractures, providing ductile behavior and warning before failure. This is critical for seismic moment frame connections.

Q: Can I use A992 for base plates? A: While A992 can be used for base plates, A36 is more common and economical. Base plates are typically cut from A36 plate stock. Use A992 only if the base plate thickness is driven by connection forces requiring higher strength.