What is the ASTM A572 Standard or Specification？

 

What is the ASTM A572 Standard or Specification? A Comprehensive Guide for Structural Steel Applications

 

The ASTM A572 standard is a specification developed by ASTM International for high-strength low-alloy (HSLA) columbium-vanadium structural steel used in construction and engineering projects. Known for its strength-to-weight ratio, weldability, and versatility, it covers five grades—42, 50, 55, 60, and 65—with astm a572 gr 50 being the most widely used.

As a leading astm a572 steel supplier in China, Gangsteel provides plates, bars, and shapes compliant with ASTM A572/A572M, ideal for bridges, buildings, and heavy machinery.

This article provides a professional, problem-solving guide to the astm a572 specification, detailing its scope, grades, properties, and applications to assist engineers, fabricators, and procurement teams in selecting the right material.

1. Scope of the ASTM A572 Standard

 

The ASTM A572/A572M standard specifies requirements for HSLA structural steel plates, shapes, sheet piling, and bars intended for riveted, bolted, or welded construction. It emphasizes high strength and enhanced atmospheric corrosion resistance, making it suitable for structural applications where weight reduction and durability are critical. The standard covers:

• Grades: 42, 50, 55, 60, and 65, each with increasing minimum yield strengths (42 ksi to 65 ksi).
• Applications: Bridges, buildings, construction equipment, transmission towers, and freight cars.
• Forms: Plates (up to 4 in. thick), bars, structural shapes (e.g., beams, channels, angles), and sheet piling.
• Conditions: As-rolled, normalized, or thermo-mechanically controlled processed (TMCP).

Gangsteel’s a572 gr 50 steel and other grades meet these requirements, ensuring compliance with ASME, EN, JIS, and DIN for global projects.

2. Grades and Mechanical Properties

 

The ASTM A572 standard defines five grades based on minimum yield strength, each suited for specific load requirements:

Grade	Yield Strength (Min ksi/MPa)	Tensile Strength (Min ksi/MPa)	Elongation (in 8 in./200mm, %)	Elongation (in 2 in./50mm, %)
42	42/290	60/415	20	24
50	50/345	65/450	18	21
55	55/380	70/485	17	20
60	60/415	75/520	16	18
65	65/450	80/550	15	17

• Grade 50: The most common, used in a572 gr 50 plate for bridges and buildings due to its balanced strength and cost.
• Grade 55: Offers higher strength for machinery, as in astm a572 gr 55.
• Grade 60: Suits heavy equipment, per astm a572 gr 60.
• Grade 65: Highest strength for critical applications, per astm a572 gr 65.

These astm a572 mechanical properties ensure versatility, with optional Charpy impact testing (≥ 27 J at 0°C) for low-temperature performance.

3. Chemical Composition

 

The astm a572 gr 50 chemical composition and other grades include columbium and vanadium for strength:

Element	Gr 50 (%)	Gr 55 (%)	Gr 60 (%)	Gr 65 (%)
Carbon (C)	≤ 0.23	≤ 0.25	≤ 0.26	≤ 0.23-0.26
Manganese (Mn)	≤ 1.35	≤ 1.35	≤ 1.35	≤ 1.35-1.65
Phosphorus (P)	≤ 0.04	≤ 0.04	≤ 0.04	≤ 0.04
Sulfur (S)	≤ 0.05	≤ 0.05	≤ 0.05	≤ 0.05
Silicon (Si)	≤ 0.40	≤ 0.40	≤ 0.40	≤ 0.40
Vanadium (V)	≤ 0.01-0.15	≤ 0.01-0.15	≤ 0.01-0.15	≤ 0.01-0.15
Columbium (Nb)	≤ 0.005-0.05	≤ 0.005-0.05	≤ 0.005-0.05	≤ 0.005-0.05
Copper (Cu, optional)	≥ 0.20	≥ 0.20	≥ 0.20	≥ 0.20

The low carbon equivalent (CE = C + (Mn + Si)/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15) ensures weldability across forms like a572 gr 50 round bar and astm a572 plate.

4. Equivalent Grades

 

A572 grades have international equivalents for global compatibility:

ASTM Grade	EN 10025	JIS G3106	GB/T 1591	BS
Gr 50	S355JR	SM490A	Q345B	50B/C
Gr 55	S355J2	SM490B	Q345C	50D/E
Gr 60	S420MC	SM520B	Q390B	50F
Gr 65	S460Q	SM570	Q420B	55C/EE

The astm a572 gr 50 equivalent material like S355JR is widely used in Europe, while astm a572 gr 65 equivalent like S460Q suits high-strength needs.

5. Dimensions and Forms

 

A572 is available in:

• Plates: astm a572 gr 50 plate (6-200mm thick, 1500-3200mm wide, up to 18000mm long).
• Round Bars: a572 gr 50 round bar (10-150mm diameter).
• Shapes: Wide-flange beams, channels, angles, and HSS.
• Sheets: 1.5-6mm thick.

Dimension	Available Range
Thickness (Plates)	6mm - 200mm
Width (Plates)	1500mm - 3200mm
Length (Plates)	Up to 18000mm
Diameter (Bars)	10mm - 150mm

Gangsteel offers customization like cutting and testing.

6. Applications

 

The astm a572 gr 50 structural steel and higher grades are used in:

• Bridges: Girders and supports for a572 gr 50 bridge steel plate.
• Buildings: Columns and seismic frames.
• Machinery: Cranes and excavators, with astm a572 gr 60 for heavier loads.
• Infrastructure: Transmission towers, railcars.

7. Weldability and Fabrication

 

A572’s low carbon equivalent ensures weldability, with recommended fillers like AWS E7018 (SMAW) or ER70S-6 (GMAW). Preheat (10-110°C for thicker sections) may be needed per AWS D1.1 to prevent cracking, especially for a572 gr 60 steel.

 

8. FAQ – Frequently Asked Questions about ASTM A572 Standard

 

1. What is the ASTM A572 standard?

A specification for HSLA structural steel, covering grades 42 to 65 for construction.

2. What are the mechanical properties of A572 Gr 50?

Min yield 345 MPa, tensile 450 MPa, per astm a572 gr 50 mechanical properties.

3. What is the chemical composition of A572 Gr 50?

Low carbon with alloys, per astm a572 gr 50 chemical composition.

4. What are the equivalent grades for A572?

Gr 50: EN S355JR; Gr 65: EN S460Q, per astm a572 gr 50 equivalent material.

5. What forms does A572 come in?

Plates, bars, shapes, per astm a572 plate.

6. Where can I buy A572 steel?

Gangsteel, an ASTM A572 Grade 50 steel supplier China.

 

9. Why Buy from GANGSTEEL?

Gangsteel offers a572 50 steel plate, astm a572 gr 42, astm a572 gr 55, astm a572 gr 60, and astm a572 gr 65 with stock, fast delivery, and MTC certification.