------------ | ----------------- | ------------ | ------------ | -------------------------- | | ASTM A992 | W-shapes | 50 | 65 | Standard beams and columns | | ASTM A572 Gr 50 | Plates, HSS | 50 | 65 | General structural | | ASTM A36 | Shapes, plates | 36 | 58 | Light framing, base plates | | ASTM A913 | Quenched W-shapes | 50-65 | 65-80 | High-ductility seismic | | EN 10025 S235 | European | 33 (235 MPa) | 51 (360 MPa) | Light structures | | EN 10025 S355 | European | 50 (355 MPa) | 62 (430 MPa) | Standard Euro structures | | AS 3678 300PLUS | Australian | 50 (300 MPa) | 60 (440 MPa) | Standard Australian | | AS 3678 350W | Australian | 50 (350 MPa) | 62 (480 MPa) | Heavy Australian | | CSA G40.21 350W | Canadian | 50 (350 MPa) | 65 (480 MPa) | Standard Canadian | | CSA G40.21 300W | Canadian | 44 (300 MPa) | 60 (450 MPa) | Light Canadian |

How to Use

1. Select your design code: AISC 360, EN 1993, AS 4100, or CSA S16.
2. Choose structural element: beam, column, tension member, or connection.
3. Set design criteria: strength, ductility, weldability, toughness.
4. Compare grades: mechanical properties, availability, cost index.
5. Review recommendations: best-match grade with code-compliant Fy/Fu values.

Grade Selection Guidelines

• Standard building frames: A992 (US), S355 (EU), 300PLUS (AU), 350W (CA)
• Seismic/welded moment frames: A913 Gr 65 (US), S355 N/NL (EU), 350W (CA)
• Base plates and connection plates: A36 (US), S235 (EU), 250 (AU), 300W (CA)
• High-strength columns: A992 (US), S460 (EU), 400 (AU), 350W (CA)

Design Guidance

Key Design Parameters

When performing structural steel design calculations, the following parameters govern the design:

• Material properties: Yield strength (Fy) and tensile strength (Fu) determine section capacity. For US projects, common grades include A992 (Fy=50 ksi) for W-shapes and A36 (Fy=36 ksi) for angles and plates.
• Design method: LRFD (Load and Resistance Factor Design) or ASD (Allowable Stress Design). LRFD applies load factors >1.0 and resistance factors <1.0 for consistent reliability across limit states.
• Load combinations: Per ASCE 7-22, the governing combination depends on the direction and magnitude of each load type. Typically 1.2D + 1.6L governs for gravity-dominated cases.
• Limit states: Strength (ultimate) and serviceability (deflection, vibration). Both must be checked per the applicable design code.
• Applicable codes: AISC 360-22 (US), EN 1993-1-1 (EU), AS 4100 (Australia), CSA S16 (Canada).

Design Procedure

1. Establish design criteria: code edition, material grade, design method (LRFD/ASD)
2. Determine loads and applicable load combinations
3. Analyze structure for internal forces (axial, shear, moment, torsion)
4. Check member strength for all applicable limit states
5. Verify serviceability criteria (deflection, drift, vibration)
6. Detail connections to transfer calculated forces

Worked Example

Problem: Design a structural element for the following conditions:

Span/Height: 15 ft | Load: 50 kips (factored) | Section: W12×65 (A992, Fy=50 ksi) | Code: AISC 360-22 LRFD

Solution:

• Demand: Pu = 50 kips (axial compression)
• Section properties: A = 19.1 in², rx = 5.28 in, ry = 3.02 in
• Slenderness: KL/r = 1.0 × 15 × 12 / 3.02 = 59.6 (controls about weak axis)
• Critical stress: Fcr per AISC Eq E3-2 (intermediate slenderness range)
• Design strength: φcPn = 0.9 × Fcr × Ag — Verify against applied load
• Interaction: Check combined forces per AISC Chapter H if applicable

Result: Section is adequate if φcPn ≥ Pu (50 kips).

Frequently Asked Questions

What design codes does this calculator support?

This calculator supports AISC 360-22 (US LRFD and ASD), EN 1993-1-1 (Eurocode 3), AS 4100 (Australia), and CSA S16 (Canada). Each code edition is verified against the respective design standard. Select your governing code in the calculator interface before entering loads.

How accurate are the results from this calculator?

Results are verified against published design examples and textbook solutions. The calculation engine uses the exact code provisions from the applicable standard. Always verify critical results independently and have designs reviewed by a licensed Professional Engineer. Results are preliminary until independently verified.

Can I save and export my calculations?

Registered users can save calculations to their account for later reference. Currently 10 calculations per hour and 50 per day are available on the free tier. Pro subscription ($49/month) increases limits to 500 calculations per month with PDF export capability.

Frequently Asked Questions

What is the difference between A36 and A992 steel? A992 (Fy=50 ksi) is 39% stronger in yield than A36 (Fy=36 ksi) for roughly 5-10% higher material cost. A992 has tighter carbon equivalent (CE) limits for better weldability and is the default specification for W-shapes in the US. A36 is still used for plates, angles, and base plates where the lower strength is adequate and cost savings matter.

What does the steel grade number mean (e.g., S355, 350W)? For EN 10025, the number after S is the minimum yield strength in MPa — S355 has Fy = 355 MPa (50 ksi). For ASTM, A992 and A572 Gr 50 have Fy = 50 ksi. For AS 3678, 350W has Fy = 350 MPa (50 ksi). For CSA G40.21, 350W has Fy = 350 MPa (50 ksi). European grades also include impact toughness classes: JR (27J at 20C), J0 (27J at 0C), J2 (27J at -20C).

When should you specify notch-tough steel? Notch-tough (Charpy V-notch tested) steel is required per AISC 341-22 for seismic force-resisting system members in Seismic Design Categories D, E, and F. It is also specified for low-temperature applications (below 50F), dynamically loaded structures (crane runways, bridges), and through-thickness connections where lamellar tearing is a concern.

Is this steel grade selection tool free? Yes, completely free with unlimited calculations.

Charpy V-Notch Toughness Requirements

Charpy V-Notch (CVN) testing measures a steel's ability to absorb energy during fracture at a specified temperature, providing a quantitative measure of notch toughness. For structural steel applications, CVN requirements are critical in seismic, low-temperature, and dynamically loaded structures where brittle fracture must be prevented.

CVN Testing Method (ASTM A370 / EN 10045)

A 10 mm x 10 mm x 55 mm specimen with a V-shaped notch (2 mm depth, 45-degree angle, 0.25 mm root radius) is cooled or heated to the test temperature, then struck by a pendulum hammer. The energy absorbed during fracture (in ft-lbs or Joules) is the CVN value. Higher energy = tougher steel.

Standard test temperatures per ASTM A709/A913:

• Zone 1: +70 degrees F (21 degrees C) — standard service, indoor structures
• Zone 2: +40 degrees F (4 degrees C) — cold weather, unheated buildings
• Zone 3: +10 degrees F (-12 degrees C) — severe cold, exposed structures

CVN Requirements by Climate Zone and Application

Seismic Toughness Requirements (AISC 341-22)

AISC 341-22 Section A3.2 requires CVN-tested steel for members in the seismic force-resisting system (SFRS) when:

1. The structure is in Seismic Design Category D, E, or F
2. The member thickness exceeds 2 inches (for rolled shapes) or 1.5 inches (for plates in built-up members)
3. The service temperature is below 50 degrees F (10 degrees C)

The CVN requirement for seismic applications is 20 ft-lbs at the lowest anticipated service temperature (LAST) for the member thickness group, per AISC 341 Table A3.2.

European CVN Designations (EN 10025)

EN 10025 uses letter suffixes to designate toughness grades:

Example: S355J2 = structural steel with 355 MPa yield and 27J CVN at -20C. This is the standard Euro-spec for exposed UK structures.

Australian and Canadian CVN Requirements

AS 3678 (Australia):

• 300PLUS and 300L15: CVN testing not mandated for standard building frames
• 350L0: 27J at 0C — exposed structural applications
• 350L15: 27J at -15C — cold regions (Tasmania, Alpine)

CSA G40.21 (Canada):

• 300W and 350W (without suffix): No CVN requirement (standard building)
• 350WT: 20 ft-lbs at -20C (cold applications)
• 350A: 20 ft-lbs at -45C (arctic applications — Northern Canada)

Practical CVN Specification for Structural Engineers

When specifying CVN-tested steel, include on the structural drawings:

• ASTM designation with CVN supplement (e.g., "ASTM A992 with CVN testing per Supplement S1")
• Minimum absorbed energy (e.g., "20 ft-lbs at +40F")
• Test orientation (longitudinal is standard; transverse requires explicit notation)
• Member locations where CVN applies (e.g., "All SFRS columns and braces")

CVN testing typically adds $0.02-$0.05 per pound to the steel cost and 1-2 weeks to delivery for mill orders. For stock material from a service center, CVN-tested material may carry a 10-20% premium relative to non-tested stock.

Key Design Principle: Fracture Critical vs Redundant Members

Fracture-critical members (FCMs) are those whose failure would result in partial or complete collapse of the structure. Per AASHTO/AISC, FCMs require CVN-tested steel and additional fabrication quality requirements (magnetic particle or dye penetrant testing of welds, tighter NDE acceptance criteria). In building design, FCM designation is less common than in bridges, but column transfer girders, hanger columns, and single-brace lateral frames approach fracture-critical behavior and warrant CVN specification.

Related pages

• Steel grades reference
• Steel density reference
• Steel weight calculator
• Steel weight per foot chart
• UK steel grades reference
• Steel column buckling calculator
• Fatigue assessment (EU)
• Fire protection for steel (EU)

Disclaimer (educational use only)

This page is provided for general technical information and educational use only. It does not constitute professional engineering advice. All structural designs must be verified by a licensed Professional Engineer (PE) or Structural Engineer (SE). The site operator disclaims liability for any loss or damage arising from the use of this page.