ASME SA709 Grade 50W: High-Strength Low-Alloy Structural Steel Plates
ASME SA709 Grade 50W is a high-strength, low-alloy (HSLA) weathering structural steel, primarily used for bridges, known for its enhanced atmospheric corrosion resistance, forming a protective rust-like patina in most environments, with a minimum yield strength of 50 ksi (345 MPa) and better durability than plain carbon steel without painting. It's essentially the ASME version of ASTM A709 Grade 50W, equivalent to ASTM A588 Grades A, B, or C depending on type, and is available as plates, shapes, and bars for exposed infrastructure.
ASTM A709 Grade 50W is a high-strength, low-alloy (HSLA) structural steel, commonly known as weathering steel (like COR-TEN), specified for bridge construction due to its improved atmospheric corrosion resistance, allowing it to be used bare (unpainted) in many applications; it offers a minimum yield strength of 50 ksi (345 MPa) and a minimum tensile strength of 70 ksi (485 MPa).
Key Characteristics
Type: High-Strength Low-Alloy (HSLA) Weathering Steel.
Primary Use: Fabrication of bridges and bridge components (girders, beams, etc.).
Corrosion Resistance: Substantially better than carbon steel, forming a protective rust-like patina, with an atmospheric corrosion index of 6.00 or higher.
Strength: Minimum Yield Strength of 50 ksi (345 MPa); Minimum Tensile Strength of 70 ksi (485 MPa).
Weldability: Generally excellent weldability, though specific procedures may apply.
Toughness: Good impact resistance, often specified with Charpy impact tests for critical applications.
Applications Beyond Bridges
Solar Industry: Used for support structures for solar paneling.
Other Structures: Suitable for any application needing durable, weather-resistant structural steel.
| Physical Properties | Metric | English | Comments |
|---|---|---|---|
| Density | 7.85 g/cc | 0.284 lb/in³ |
Mechanical Properties
|
Grade |
Thickness |
Yield strength 1) |
Tensile strength |
Elongation in 2" 2) |
Elongation in 8" 2) |
|---|---|---|---|---|---|
|
50W |
4.762 - 76.2 |
50 |
70 |
21 |
18 |
Chemical Composition
|
C |
Mn |
P |
S |
Si |
V |
Cr |
Ni |
Cu |
|---|---|---|---|---|---|---|---|---|
|
0.19 |
0.80 - 1.25 |
0.030 |
0.030 |
0.30 - 0.65 |
0.02 - 0.10 |
0.40 - 0.65 |
0.40 |
0.25 - 0.40 |
Available Dimensions
|
Grade |
Width |
Length |
|---|---|---|
|
50W |
1800 - 3050 |
6100 - 30480 |
| Electrical Properties | Metric | English | Comments |
|---|---|---|---|
| Electrical Resistivity | 0.0000234 ohm-cm | 0.0000234 ohm-cm | Typical steel |
|
|
|||
| Thermal Properties | Metric | English | Comments |
| Specific Heat Capacity | 0.475 J/g-°C | 0.114 BTU/lb-°F | Typical steel |
| Thermal Conductivity | 46.6 W/m-K | 323 BTU-in/hr-ft²-°F | Typical stee |
1What is A709 grade 50W steel?
ASTM A709-50W is a standard specification for structural steel primarily in the fabrication of steel bridges. ASTM A709-50W covers high strength, low allow steel structural shapes, plates and bars.
2What is the difference between astm a709 grade 50w and astm a709 grade 50?
The main difference is that ASTM A709 Grade 50W is a "weathering" steel with added alloying elements (like copper, chromium, nickel) for enhanced atmospheric corrosion resistance, allowing it to form a protective rust-like patina and often eliminating the need for painting, while Grade 50 is a standard structural steel that lacks these specific corrosion-resistant properties, though both offer similar minimum yield (50 ksi) and tensile (70 ksi) strengths. Grade 50W is specifically designed for bridge construction where natural weathering is desired for reduced maintenance.
3What are the Common Testing Requirements astm a709 grade 50w ?
ASTM A709 Grade 50W testing requires tensile tests (Yield: 50 ksi min, Tensile: 70 ksi min), specific elongation limits, and usually Charpy V-Notch impact tests for toughness, with varying chemical composition requirements (Mn, Si, Cu, etc.) depending on thickness and specific types (like 50WT/50WF), all detailed within the ASTM A6/A709 standards for structural steel used in bridges and general construction.
4Is ASME SA709 Grade 50W steel hard to drill?
ASME SA709 Grade 50W (Weathering Steel) isn't inherently "hard" like hardened tool steel but is a High Strength Low Alloy (HSLA) steel, requiring good machining practices like cobalt (HSS-Co) bits, slow speeds, high pressure, and ample cutting fluid for efficient drilling; it can be challenging due to its strength, but carbide or cobalt bits are effective for cutting through its tough, alloyed structure.
5Is ASME SA709 Grade 50W weathering steel?
Yes, ASME SA709 Grade 50W is a type of weathering steel, specifically a high-strength, low-alloy (HSLA) structural steel known for its excellent atmospheric corrosion resistance, forming a protective patina when exposed to the elements, making it ideal for bridges and structures. The 'W' in its designation stands for "weathering," and it offers superior durability compared to standard steels without needing paint or coatings.
If you want to learn more about ASTM A709 Grade 50W GNEE's products, you can send an email to info@gneesteels.com. We are more than happy to assist you.
