AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS)

AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) Product Information -:- For detailed product information, please contact sales. -: AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) Synonyms -:- For detailed product information, please contact sales. -:

AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) Product Information -:- For detailed product information, please contact sales. -: **Product Name:** AK Steel ASTM A1011, Grade 40 Hot-Rolled Carbon Steel, Structural Steel (SS) --- ### **1. Overview** AK Steel's ASTM A1011 Grade 40 is a versatile hot-rolled structural steel that offers an increased minimum yield strength of 40 ksi (275 MPa), providing a 33% strength advantage over the common Grade 30 while maintaining excellent fabricability. Positioned between standard carbon steels and higher-strength low-alloy (HSLA) grades, it serves as a cost-effective solution for applications where additional load-bearing capacity is required without the need for specialized welding procedures or microalloyed chemistry. This grade is ideal for designers seeking to optimize material thickness and weight in structural frameworks and fabricated components. --- ### **2. International Standards** This product conforms to the following widely recognized North American standard: * **ASTM A1011 / A1011M:** Standard Specification for Steel, Sheet and Strip, Hot-Rolled, Carbon, Structural, High-Strength Low-Alloy and High-Strength Low-Alloy with Improved Formability. * This product meets the requirements for **Grade 40** under the **Commercial Steel (CS)** category. It may also be supplied to meet the requirements of **Structural Steel (SS) Grade 40**, which has slightly different property minima. --- ### **3. Chemical Composition (Typical, % by Weight)** Grade 40 achieves its strength primarily through a balanced carbon-manganese chemistry, making it a classic carbon steel grade. Compositions are typically specified as maximums. | Element | Content (Maximum, unless specified) | Role & Implication | | :--- | :--- | :--- | | **Carbon (C)** | 0.15% - 0.25% (Typical range) | The primary strengthening element. Higher than Grade 33/36, providing the base for the 40 ksi yield strength. | | **Manganese (Mn)** | 0.70% - 1.00% | Essential for strength and hardenability; works synergistically with carbon. | | **Phosphorus (P)** | 0.035% max | Residual impurity; kept low to maintain ductility and weldability. | | **Sulfur (S)** | 0.035% max | Residual impurity; controlled for weldability and to prevent hot shortness. | | **Silicon (Si)** | 0.10% - 0.30% | Used as a deoxidizer (killed or semi-killed steel). | | **Copper (Cu)** | 0.20% min (when specified) | Optional element for improved atmospheric corrosion resistance per ASTM A1011. | **Key Characteristic:** As a standard carbon steel, Grade 40 does not rely on microalloying elements (like Nb or V) for strength. Its carbon equivalent (CE) is higher than lower-grade carbon steels, which must be considered during welding. --- ### **4. Physical & Mechanical Properties** Properties are measured in the as-hot-rolled condition. The steel provides a reliable increase in load capacity. | Property | Specification Minimum (Typical for CS/SS Grade 40) | Typical Value / Description | | :--- | :--- | :--- | | **Yield Strength (min)** | 40 ksi (275 MPa) | | | **Tensile Strength** | 55 ksi min (380 MPa) | Typically ranges from 55 - 75 ksi (380 - 515 MPa). | | **Elongation in 2" (min)** | 20% - 22% (varies by thickness & spec subset) | Maintains good ductility for bending and forming operations. | | **Modulus of Elasticity** | 29,000 ksi (200 GPa) | Standard for carbon steel. | | **Density** | 0.284 lb/in³ (7.85 g/cm³) | | | **Surface Finish** | Standard hot-rolled mill finish with adherent oxide scale. | Descaling is required for painting, coating, or critical welding. | --- ### **5. Key Features & Advantages** * **Higher Load Capacity:** The 40 ksi minimum yield strength allows for the design of stronger structures or the use of thinner sections compared to Grade 33/36, leading to potential weight savings. * **Good Fabricability:** Maintains acceptable formability and machinability for a wide range of structural fabrication processes, including bending, punching, and drilling. * **Cost-Effective Strength Upgrade:** Provides a significant strength increase over lower grades without venturing into the higher cost bracket of microalloyed HSLA steels. * **Weldability:** Weldable using all common processes, though careful attention to procedure (such as mild preheat for thicker sections) is recommended due to its higher carbon equivalent compared to lower grades. * **Wide Availability:** Readily available from steel service centers in a full range of thicknesses and widths. --- ### **6. Product Applications** ASTM A1011 Grade 40 is specified for structural applications requiring a moderate boost in strength and load-bearing performance. * **Structural Framing & Construction:** Heavier-duty building frames, truss chords, purlins, girts, and base plates where design loads exceed the capacity of Grade 36. * **Industrial Equipment & Machinery:** Machine bases, support frames, crane runways, and guarding for heavy machinery. * **Transportation & Trailers:** Trailer main beams, dump truck subframes, flatbed components, and container flooring. * **Agricultural Equipment:** Chassis components, loader arms, and implement frames subject to moderate stress. * **Storage & Racking:** Uprights and beams for medium-to-heavy-duty pallet racking systems and industrial shelving. * **Bridge & Infrastructure:** Secondary structural members, diaphragms, and miscellaneous steel in bridge work. --- ### **7. Fabrication & Processing Notes** * **Descaling:** Mill scale must be removed via pickling, abrasive blasting, or grinding prior to welding or painting to ensure quality and adhesion. * **Forming:** Good for cold bending; however, the minimum recommended inside bend radius may be slightly larger than for lower-strength grades (e.g., 1.5t to 2t, where t is thickness). * **Welding:** Requires more attention than lower-carbon steels. Use of low-hydrogen electrodes (E7018) and processes (MIG/FCAW with deoxidized wire) is strongly recommended. Preheating at 50-150°F (10-65°C) is advisable for material over 0.75 inches thick or in restrained joints to prevent hydrogen-induced cracking. * **Machining:** Machines well with proper tool geometry and coolants. Produces discontinuous chips. --- **Disclaimer:** *This description is for informational purposes. AK Steel is now part of Cleveland-Cliffs Inc.* For all engineering and procurement purposes, it is essential to consult the latest official **ASTM A1011** standard and the certified **Mill Test Report (MTR)** or **Technical Data Sheet (TDS)** from the manufacturer. The specific requirements for **Grade 40** can differ between the *Commercial Steel (CS)* and *Structural Steel (SS)* designations within A1011, particularly for tensile strength and elongation. Always verify the exact specifications applicable to your order. -:- For detailed product information, please contact sales. -: AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) Specification Dimensions Size： Diameter 20-1000 mm Length <4585 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) Properties -:- For detailed product information, please contact sales. -:

Applications of AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) -:- For detailed product information, please contact sales. -: Chemical Identifiers AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) -:- For detailed product information, please contact sales. -:

Packing of AK Steel ASTM A 1011, Grade 40 Hot Rolled Carbon Steel, Structural Steel (SS) -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1056 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition