What is A500 Hss Properties used for in structural engineering?

A500 Hss 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.

A500 HSS Properties — Grade B & Grade C Yield Strength, Applications & Design

ASTM A500 covers cold-formed welded and seamless carbon steel structural tubing in round (HSS), square (HSS), and rectangular (HSS) shapes. Grade B (Fy=46 ksi) and Grade C (Fy=50 ksi) are the most commonly specified grades for structural applications. This page covers A500 mechanical properties, chemical composition, HSS applications, connection considerations, and AISC 360 design guidance.

Quick access: A1085 HSS → | US Steel Grades → | Column Calculator → | Section Properties →

A500 HSS Mechanical Properties

Grade Comparison

Property	Grade B	Grade C	Grade D	Grade A
Fy (ksi)	46	50	36	33
Fu (ksi)	58	62	58	45
Fy (MPa)	317	345	248	228
Fu (MPa)	400	428	400	310
Elongation (2 in.)	23% min	21% min	23% min	25% min

Note: Grade D and Grade A are rarely specified for structural applications. Grade B and Grade C dominate structural HSS usage.

Grade B vs Grade C

Attribute	Grade B	Grade C
Fy	46 ksi (317 MPa)	50 ksi (345 MPa)
Fu	58 ksi (400 MPa)	62 ksi (428 MPa)
Fy/Fu ratio	0.79	0.81
Cost	Baseline	+5-10%
Availability	Excellent	Excellent
Common use	Secondary framing, trusses	Columns, primary framing

Yield Strength by Shape and Size

A500 allows yield strength reductions for thicker walls and larger perimeters:

Grade	Perimeter/Thickness	Fy Reduction
B	Perimeter/t ≤ 56	No reduction
B	56 < Perimeter/t ≤ 80	Fy = 42 ksi
B	Perimeter/t > 80	Fy = 38 ksi
C	Perimeter/t ≤ 56	No reduction
C	56 < Perimeter/t ≤ 80	Fy = 46 ksi
C	Perimeter/t > 80	Fy = 42 ksi

Important: Always check the perimeter-to-thickness ratio when designing with thick-walled or large HSS sections. The reduction applies to round, square, and rectangular HSS.

A500 Chemical Composition

Heat Composition Requirements

Element	Grade B Max (%)	Grade C Max (%)
Carbon (C)	0.26	0.23
Manganese (Mn)	—	1.35
Phosphorus (P)	0.035	0.035
Sulfur (S)	0.035	0.035

Note: Grade C has tighter carbon control (0.23% max) and specifies manganese, contributing to its higher strength and better weldability.

HSS Shape Types

Round HSS (HSS)

Designation	OD (in)	Wall (in)	Weight (lb/ft)
HSS 6.625x0.280	6.625	0.280	18.97
HSS 8.625x0.322	8.625	0.322	28.55
HSS 10.75x0.365	10.750	0.365	40.48
HSS 12.75x0.375	12.750	0.375	49.56

Square HSS (HSS)

Designation	Width (in)	Wall (in)	Weight (lb/ft)
HSS 6x6x3/8	6.000	0.375	27.38
HSS 8x8x1/2	8.000	0.500	48.85
HSS 10x10x5/8	10.000	0.625	75.52
HSS 12x12x3/4	12.000	0.750	106.73

Rectangular HSS (HSS)

Designation	Width (in)	Height (in)	Wall (in)	Weight (lb/ft)
HSS 6x4x3/8	6.000	4.000	0.375	21.97
HSS 8x6x1/2	8.000	6.000	0.500	41.42
HSS 10x6x5/8	10.000	6.000	0.625	57.19
HSS 12x8x3/4	12.000	8.000	0.750	85.07

Applications

When to Use HSS

Application	Recommended Grade	Shape
Columns (buildings)	Grade C	Square or Rectangular
Trusses	Grade B or C	Round or Square
Architectural framing	Grade B	Round or Rectangular
Bollards	Grade B	Round
Sign structures	Grade B	Round
Light poles	Grade B	Round
Stadium seating	Grade B	Rectangular
Crane booms	Grade C	Rectangular

HSS vs W-Shapes for Columns

Attribute	HSS (Square)	W-Shape
Buckling resistance	Excellent (equal ry/ry)	Good (rx > ry)
Aesthetic	Clean, modern	Exposed flanges
Connection complexity	Higher	Lower
Fire resistance	Better (less surface area)	Lower
Cost	Higher	Lower
Availability	Good	Excellent

Connection Considerations

HSS connections require special attention compared to open sections.

HSS-to-HSS Connections

Connection Type	Limit States	Notes
T-joint (branch on chord)	Chord plastification, branch effective width, punching shear	AISC 360 Table K1
K-joint (gap or overlap)	Chord plastification, branch effective width, punching shear	AISC 360 Table K1
Corner joint	Chord wall failure	Special detailing required

HSS-to-Plate Connections

Connection Type	Method	Notes
Through-bolt	Through-wall bolts	Requires access holes
Blind bolts	Side-mounted bolts	No interior access needed
Welded plate	Fillet or CJP weld	Standard fabrication
Cleat	Bolted angle cleat	Field-bolted convenience

AISC 360 HSS Connection Design

The AISC 360 specification Chapter K covers HSS connection design:

Table K1 — HSS-to-HSS truss and frame connections
Table K2 — HSS-to-HSS moment connections
Table K3 — HSS transverse plate connections
Table K4 — HSS longitudinal plate connections

Weldability

A500 HSS has good weldability for both Grade B and Grade C.

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

Weld Types

Joint	Weld Type	Notes
HSS-to-plate	Fillet weld	Standard for most connections
HSS-to-HSS	Fillet or CJP	CJP for moment connections
End plate	CJP or fillet	CJP for full-strength connections

Welding Challenges

HSS wall thickness is typically thin (3/16" to 3/4"), requiring:

Lower heat input to prevent burn-through
Proper fit-up (gaps reduce weld strength)
Qualified welding procedures for thin material

AISC 360 Design with A500

Worked Example — HSS Column

Problem: Check an HSS 8x8x3/8 Grade C column, KL=12 ft.

Given:

HSS 8x8x3/8: Ag = 10.9 in², rx = ry = 3.05 in
KL = 12 ft = 144 in

Solution:

KL/r = 144/3.05 = 47.2
Fe = π²E/(KL/r)² = π²(29,000)/47.2² = 128.4 ksi
Fy/Fe = 50/128.4 = 0.389 < 2.25
Fcr = 0.658^0.389 × 50 = 0.828 × 50 = 41.4 ksi
Pn = Fcr × Ag = 41.4 × 10.9 = 451 kips
LRFD: phiPn = 0.90 × 451 = 406 kips
ASD: Pn/Omega = 451/1.67 = 270 kips

Worked Example — HSS Truss Chord

Problem: Check the chord plastification for an HSS 6x6x3/8 Grade B truss chord with a 4x4x1/4 Grade B branch.

Given:

Chord: HSS 6x6x3/8 (B=6", t=0.375", Fy=46 ksi)
Branch: HSS 4x4x1/4 (b1=4", t1=0.25")
Gap g = 2"

Solution:

B/t = 6/0.375 = 16 (compact, ≤ 33)
Pn = Fy × t² × (2.5 + 3.5(b1/B)) / (1 - 0.81(g/B))
Pn = 46 × 0.375² × (2.5 + 3.5(4/6)) / (1 - 0.81(2/6))
Pn = 46 × 0.1406 × (2.5 + 2.333) / (1 - 0.27)
Pn = 6.47 × 4.833 / 0.73 = 42.8 kips
LRFD: phiPn = 0.90 × 42.8 = 38.5 kips per branch

A500 vs A1085

Attribute	A500 Grade C	A1085
Fy	50 ksi	50 ksi
Fu	62 ksi	65 ksi
Fy/Fu ratio	0.81	0.85 max
Wall tolerance	±10%	±10%
Charpy testing	Not required	Supplementary available
Seismic suitability	Ordinary	Enhanced
Cost	Baseline	+10-15%

Rule of thumb: Use A1085 for seismic moment frames and applications requiring guaranteed ductility. Use A500 Grade C for all other structural HSS applications.

Calculator

Design steel members with A500 HSS using our free calculators:

Column Buckling Calculator → — HSS compression capacity with KL/r
Beam Capacity Calculator → — HSS flexural strength
Bolted Connection Calculator → — HSS connection design
Section Properties → — Full AISC section database including HSS

FAQ

Q: What is the yield strength of A500 Grade B HSS? A: ASTM A500 Grade B has a minimum yield strength of 46 ksi (317 MPa) and a minimum tensile strength of 58 ksi (400 MPa). Grade B is the most commonly specified grade for structural HSS applications.

Q: What is the difference between A500 Grade B and Grade C? A: Grade B has Fy=46 ksi and Fu=58 ksi. Grade C has Fy=50 ksi and Fu=62 ksi. Grade C provides 9% higher yield strength for a 5-10% cost premium. Grade C is preferred for columns and primary structural members.

Q: When should I use A500 vs A1085 HSS? A: Use A500 Grade C for most structural HSS applications. Use A1085 for seismic moment frames, buckling-restrained braces, and applications requiring guaranteed Fy/Fu ratio (0.85 max). A1085 has tighter quality controls and costs 10-15% more.

Q: Can I weld A500 HSS? A: Yes, A500 HSS is weldable. Use E7018 or ER70S-6 electrodes. For thin walls (under 3/16"), use lower heat input to prevent burn-through. Preheat is generally not required for thicknesses up to 3/4 inch.

Q: What is the perimeter-to-thickness ratio for A500? A: The perimeter-to-thickness ratio determines if yield strength reductions apply. For Grade B: no reduction when P/t ≤ 56, Fy=42 ksi when 56 < P/t ≤ 80, Fy=38 ksi when P/t > 80. Always check this for thick-walled or large HSS.

Q: How do I connect to HSS? A: Common methods include: welded plates (fillet or CJP welds), through-bolts (requires access holes), blind bolts (no interior access needed), and bolted angle cleats (field-bolted convenience). AISC 360 Chapter K covers HSS connection design.