Structural steel grades are essential construction materials known for their strength and versatility. These steels are specifically designed for use in building structures, offering a combination of durability, flexibility, and cost-effectiveness. Typically composed of iron and carbon, structural steel is available in various grades, each tailored to meet specific engineering requirements. It is often manufactured in pre-formed shapes such as beams, columns, and channels, making it ideal for a wide range of applications.
Table of contents
What is Structural Steel?
Producing & Testing of Structural Steel
Properties of Grade E250
Mechanical Properties of SS Grade E250
Structural material grades Types
What are The Different Grades of Structural Steel ?
Structural Steel Standards
Different Shapes of Structural cold formed steel
Strength-Weight Ratio of Structural Steel
Structural Steel vs Stainless Steel
Yield Strength of Structural cold formed steel
Tensile Strength of Structural beam
Chemical Composition of Structural Steels
E250 material Chemical Composition
Advantages and Disadvantages of structural galvanized steel
Benefits of Structural Steel Hollow Sections
Characteristic of AISI 304 & 316
S235 Steel Hollow Section Square Weight Chart
S355 Steel Density kg/m3
Mechanical Properties of Steel Grade E350
E350 steel Chemical Composition
Inspection Checklist of S235 Grade
Structural Steel and Reinforcement Steel Difference
Applications of S420 Material
What is Structural Steel?
Aspect
Details
Purpose
Construction material in various shapes
Profiles
I-beams, channels, angles, hollow sections
Fabrication Methods
– Hot Rolling: Shaping with heat
– Cold Rolling: Shaping at room temperature
– Welding: Joining sections
– Bending: Creating curves
– Recycled Steel: Melting and refining
– Raw Materials: Extraction from iron ore
Iron Extraction
– Process: Grinding taconite, magnetic separation
– Iron Ore Characteristics: Raw ore is soft; carbon adds strength
Iron-Carbon Alloy Production
– Reduction Process: Heating coke with iron ore to bond carbon with oxygen
– Carbon Content: Below 2.1% to form steel; structural steel has 0.05-0.25% carbon
Properties of Structural Steel
High strength-to-weight ratio
100% recyclable
Cost-effective
Grades
Various grades with slight composition differences for specific needs
Check Structural Steel Grade E250 Properties
Due to its remarkable properties as given below, it has become a premium construction material for infrastructure and skylines manufacturing. Find below the key points that define what properties it provides to products made using structural steel grade E250.
Properties of Grade E250
Good weldability
Good formability
Good dimensional accuracy
Toughness
Heat treatable
Sturdy construction
Mechanical Properties of SS Grade E250
Property
Value
Yield Strength
250 N/mm²
Tensile Strength
410 N/mm²
Elongation
23% minimum
View the Standard Structural Steel Materials and Standards
Structural steel is a versatile and durable material, making it highly valuable in the construction industry. Its unique combination of properties makes it suitable for a wide range of applications. When selecting structural steel for a particular project, engineers consider the material's properties to ensure optimal performance and longevity.
The following details about structural steel will provide you with comprehensive information about its characteristics and uses.
Structural material grades Types
Steel Type
Key Features
Common Uses
Carbon Steels
No major alloys; Cu ≤ 0.6%, Mn ≤ 1.6%, Si ≤ 0.6%
Structural pipes and tubing
High-Strength, Low-Alloy Steels
Mn up to 2%; trace Cr, Ni, Mo, etc.
Structural shapes and plates
Forged Steels
Uniform grain structure; enhanced strength
High-strength applications
Quenched and Tempered Alloy Steels
Heat and rapid cooling; tough and strong
High-strength structural uses
What are The Different Grades of Structural Steel ?
Steel Type
Key Features
Common Uses
A36 Steel
– Low-carbon & Good weldability
– Yield strength: 36,000 PSI
S235 Steel Are Designed to Have Good Strength / Weight Ratio
This structural steel grade is known for offering a good strength-to-weight ratio. Its yield strength of 235MPa means it can withstand significant loads without permanent damage. This balance between strength and weight makes it ideal for applications where reducing weight is crucial without compromising durability or performance.
Strength-Weight Ratio of Structural Steel
Aspect
Description
Strength-to-Weight Ratio
Strength divided by density; indicates material efficiency.
Purpose
Categorizes materials based on their suitability for specific uses.
Example: Concrete
– High compression strength-to-weight ratio.
– Less effective in tension strength.
– Ideal for compression-focused applications.
Usage
Helps determine material suitability for various structural needs.
Structural Steel vs Stainless Steel
Aspect
Structural Steel
Stainless Steel
Materials
Iron + <1.5% carbon
Iron + Chromium, sometimes Nickel, Titanium
Common Uses
Beams in high rises, structural applications
Cutlery, medical materials, decorative plates
Strength & Hardness
Higher iron content; very hard
Slightly weaker; more malleable at room temperature
Ductility
Less ductile compared to stainless steel
Higher ductility due to added nickel
Cost
Less expensive
More expensive due to alloying elements and production
Magnetism
Generally magnetic
Typically non-magnetic; some grades may be magnetic
Temperature
Higher melting point
Lower melting point, but overlap with structural steel
Yield Strength of Structural cold formed steel
Grade
Minimum Yield Strength
N/mm2 (MPa)
PSI
S235
235 N/mm2
33 000
S275
275 N/mm2
36 000
S355
355 N/mm2
50 000
Tensile Strength of Structural beam
Grade
Tensile Strength MPa
S235
360 – 510 MPa
S275
370 – 530 MPa
S355
470 – 630 MPa
Chemical Composition of Structural Steels
EU Grade
Mn%
C%
Si%
S%
P%
S235
1.60 max
0.22 max
0.05 max
0.05 max
0.05 max
S275
1.60 max
0.25 max
0.05 max
0.05 max
0.04 max
S355
1.60 max
0.23 max
0.05 max
0.05 max
0.05 max
Structural Steel Grade E350 Have a Carbon Content Between 0.1 and 0.3%
E250 material Chemical Composition
Grade
C
S
Mn
P
Si
Carbon Equivalent (CE), Max
IS 2062 E350
0.20
0.045
1.50
0.045
0.45
0.42
S420 Steel Material is Very Durable and is Resistant to Mold, Moisture
This grade of structural steel is known for its durability and resistance against moisture conditions where its shape might otherwise be affected. Due to its chemical composition, it offers this protective feature, making it highly applicable for long-term construction applications where durability is essential.
Advantages and Disadvantages of structural galvanized steel
Advantags
Disadvantages
Higher strength/weight ratio
Susceptible to corrosion
High durability
High fire resistance cost
Versatility due to good ductility
high maintenance costs
Sustainability
Buckling is an issue
Benefits of Structural Steel Hollow Sections
Aspect
Details
High Strength-to-Weight Ratio
– Economical due to structural efficiencies.
– High radii of gyration enhance compression performance and reduce weight.
Aesthetic Appeal
– Favored for architectural use.
– Smooth sides, rounded corners, and closed sections are ideal for exposed structures.
Less Surface Area for Coatings
– Rectangular and square HSS have ~2/3 the surface area of open sections with similar capacity.
– Reduces surface preparation, painting material, labor, and fireproofing.
Closed Section
– Effective at resisting torsional loads.
– Minimal surfaces collect dust and debris, suitable for clean environments.
Characteristic of AISI 304 & 316
Characteristics
304 stainless steel
316 stainless steel
Weldability
High
Good
Corrosion resistance
Excellent
Even better
Magnetic
No
No
Hardens during cold forming
Yes
Yes
Machinability (annealed)
Fair, but better than 316
Fair
Resists elevated temperatures
High
High
Formability
Very good
Good
Maximum intermittent service temperature
1562°F
1562°F
S235 Steel Hollow Section Square Weight Chart
Section Index
Weight
Area
Sizes
Corner Radius
Axis 1-1
Axis 2-2
Depth
Width
Thickness
ra
ri
Ix
Sx
rx
ly
Sy
ry
Vpy
Vpz
Ax
d
bf
tf
tw
(lb/ft)
(in2)
(in)
(in)
(in)
(in)
(in)
(in)
(in 4)
(in2)
(in)
(in 4)
(in2)
(in)
(in)
(in)
HSSQ22x22x0,875
244 7/8
67 2/7
22
22
4/5
4/5
4/5
1 5/8
4970
530
8 3/5
4970
530
8 3/5
11
11
HSSQ20x20x0,75
4/7 191
52 3/5
20
20
2/3
2/3
2/3
1 2/5
3230
378
7 5/6
3230
378
7 5/6
10
10
HSSQ22x22x0,75
212
58 1/5
22
22
2/3
2/3
2/3
1 2/5
4350
462
8 2/3
4350
462
8 2/3
11
11
HSSQ20x20x0,875
221
60 4/5
20
20
4/5
4/5
4/5
1 5/8
3670
433
7 7/9
3670
433
7 7/9
10
10
HSSQ20x20x0,625
161 2/5
44 2/7
20
20
4/7
4/7
4/7
1 1/6
2750
320
7 7/8
2750
320
7 7/8
10
10
HSSQ20x20x0,5
130 1/2
35 4/5
20
20
1/2
1/2
1/2
1
2260
261
8
2260
261
8
10
10
S355 Steel Density kg/m3
Material Property
Value
Density Ï
≈ 7850 kg/m3
Unit weight γ
≈ 78.5 kN/m3
Modulus of elasticity E
(Young’s modulus)
210000 MPa
Shear modulus G
G = E / [2 ⋅ (1 + ν) ] ≈ 81000 MPa
Poisson’s ratio in elastic range ν
0.30
Coefficient of linear thermal expansion α
12 ×10-6 °K-1
Mechanical Properties of Steel Grade E350
Tensile Strength in Mpa
490 min.
Yield Strength in Mpa
320 min.
Hardness in BHN
170 – 207
Elongation in %
22 min.
Reduction of Area in %
–
Impact in Joule
–
E350 steel Chemical Composition
Carbon
C %
0.200 max.
Phosphorus
P %
0.045 max.
Silicon
Si %
0.450 max.
Manganese
Mn %
1.550 max.
Sulphur
S %
0.045 max.
Iron
Fe %
Balance
Inspection Checklist of S235 Grade
Design code
Purchase order specification
Steel Structure Manufacture Quality Control Plan
Steel Structure Inspection and test plan
Steel Structure Data Sheet
Steel Structure Approved Drawings
Steel Structure Strength calculation sheets
Steel Structure Material Test Reports
Certificate No.
Heat or cast No.
Chemical composition.
Mechanical properties.
Heat treated condition.
NDE applied and results.
Welders properly qualified
Test coupons compiled where necessary
Dimensional check on pre-drilled parts
Correct fastening being used
Protection of protruding parts
Shipping and other marks
Structural Steel and Reinforcement Steel Difference
Aspect
Structural Steel
Reinforced Steel
Primary Use
Forming the frames of buildings and structures
Reinforcing concrete and masonry structures
Materials
Various types of steel, including carbon-manganese, high-strength low-alloy
Hot rolled deformed bars, mild steel plain bars, cold worked steel reinforcements
Forms
Beams, braces, plates, columns in various shapes (S, L, H, C, I, HSS, T, Pipe)
Steel bars (rebar) in various forms and treatments (hot rolled, cold worked, etc.)
Shapes
Defined by cross-sectional shapes such as S, L, H, C, I, HSS, T, Pipe
Typically round or square bars, not defined by cross-sectional shapes
Key Characteristics
High strength, flexibility
Provides tensile strength to complement concrete’s compressive strength
Typical Applications
Used in constructing beams, columns, bridges
Used within concrete to handle tensile stresses, e.g., in slabs, beams
Strength Focus
Focuses on overall structural strength and load-bearing capacity
