AISI 1137 Steel Rod/Bar

AISI 1137 Steel Rod, annealed at 790°C (1450°F) Product Information -:- For detailed product information, please contact sales. -: AISI 1137 Steel Rod, annealed at 790°C (1450°F) Synonyms -:- For detailed product information, please contact sales. -:

AISI 1137 Steel, annealed at 790°C (1450°F) Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: AISI 1137 Steel, Annealed at 790°C (1450°F)** **Overview** AISI 1137 steel subjected to a full annealing heat treatment at 790°C (1450°F) represents this free-machining, resulfurized steel in its softest, most ductile, and most dimensionally stable condition. This specific thermal cycle is designed to produce a coarse, uniform microstructure through complete austenitization followed by controlled slow cooling. The treatment maximizes machinability, completely relieves internal stresses, and optimizes cold formability, making it the ideal preparatory state for manufacturing complex components that require extensive machining or forming prior to any final heat treatment or use. --- #### **1. Chemical Composition (Nominal, Weight %)** The composition strictly conforms to AISI/SAE 1137 specifications, engineered for free-machining performance. | Element | Carbon (C) | Manganese (Mn) | **Phosphorus (P)** | **Sulfur (S)** | Silicon (Si) | Iron (Fe) | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **Content (%)** | 0.32 - 0.39 | 1.35 - 1.65 | **0.040 - 0.090** | **0.080 - 0.130** | 0.15 - 0.35 | Balance | * **Metallurgical Significance for Annealing:** * **Carbon (0.32-0.39%):** This carbon level results in an annealed microstructure of ferrite and pearlite. The 790°C temperature ensures complete transformation to austenite, allowing for homogenization before slow cooling to the softest possible state. * **Manganese (1.35-1.65%) & Sulfur (0.08-0.13%):** Form **manganese sulfide (MnS) inclusions**. These remain unchanged during annealing and are the primary source of the steel's superior machinability. They act as chip breakers during cutting. * **Phosphorus (0.04-0.09%):** Strengthens the ferrite in solid solution. The slow cool allows for a more uniform distribution. --- #### **2. Physical & Mechanical Properties (Typical, Annealed at 790°C / 1450°F)** *Annealing produces the minimum hardness and maximum ductility for this grade.* * **Hardness:** **~150-185 HB** (Approximately 80-88 HRB) * **Tensile Strength (Ultimate):** 500 - 630 MPa (73 - 91 ksi) * **Yield Strength (0.2% Offset):** 275 - 400 MPa (40 - 58 ksi) * **Elongation (in 50mm):** 20% - 28% * **Machinability:** **~85-95%** (Compared to 100% for AISI 1212). **Exceptional.** The soft, coarse microstructure combined with MnS inclusions allows for the highest cutting speeds, lowest cutting forces, excellent chip control, superior surface finish, and maximum tool life achievable with this steel. * **Microstructure:** **Coarse lamellar pearlite in a ferrite matrix.** If cooled very slowly, the cementite may become partially spheroidized. * **Dimensional Stability:** **Excellent.** The annealing process effectively eliminates all residual stresses from prior processing (rolling, forging). * **Cold Formability:** Very good for moderate operations, though limited by anisotropic properties from MnS stringers. --- #### **3. Heat Treatment Process: Full Annealing** The standard full annealing process involves: 1. **Austenitizing:** Heat uniformly to **790°C (1450°F)**, held to ensure complete transformation to austenite throughout the cross-section. 2. **Slow Furnace Cooling:** The key step. The steel is cooled **inside the furnace** at a controlled, slow rate (typically furnace cooled) to below 550°C (1020°F), then air cooled. 3. **Result:** Produces the softest, most stable, and most homogeneous condition for AISI 1137, with a coarse-grained equilibrium microstructure. --- #### **4. Product Applications** Annealed AISI 1137 is specified for manufacturing processes where ease of machining or forming is the paramount concern. * **Complex, High-Precision Machined Parts:** Intricate gears, splined shafts, valve bodies, and components with thin walls or deep holes requiring extensive, stable machining. * **Automatic Screw Machine Parts:** Ideal for producing complex components on Swiss-type or multi-spindle automatics where maximum tool life and minimum distortion are critical. * **Cold Forming & Forging Blanks:** Used for parts requiring significant cold forging, extrusion, or drawing before any final treatment. * **Fastener Manufacturing:** Wire or rod for cold heading of bolts and screws where extreme ductility is needed. * **Tooling and Die Blanks:** Base material for molds and fixtures that will be machined to intricate shapes. * **Prototype and Low-Volume Parts:** Preferred for development due to forgiving machining behavior and minimal distortion. --- #### **5. Relevant International Standards** This condition is specified by referencing the base material standard and the annealed condition. * **ASTM (USA):** * **ASTM A29/A29M:** Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought and Cold-Finished (Specify "Annealed" condition). * **SAE (USA - Automotive):** **SAE J403, J412** (Grade 1137). * **UNS (Unified Numbering System):** **G11370** * **ISO (International):** * **ISO 683-18:** Heat-treatable steels, alloy steels and free-cutting steels – Part 18: Bright products. Condition "+A" for annealed. * **DIN (Germany):** **DIN EN 10087:** Free-cutting steels (Comparable to **35S20**, **1.0726**). * **JIS (Japan):** JIS G4804: Free-cutting steels (Similar to **SUM 41**). --- #### **6. Key Advantages & Considerations** * **Advantages:** * **Maximum Machinability:** Provides the best possible cutting performance for AISI 1137, optimizing production speed and cost. * **Superior Dimensional Stability:** The stress-free state virtually eliminates machining distortion, crucial for tight tolerances. * **Excellent Cold Formability:** Enables more severe cold forming operations than harder conditions. * **Uniform Microstructure:** Creates a homogeneous starting point for consistent results in subsequent processing. * **Considerations:** * **Low As-Supplied Strength:** The material is soft and not suitable for structural use without subsequent hardening. * **Anisotropic Properties:** Ductility and toughness remain highly directional (poor in transverse direction) due to MnS stringers. * **Not Weldable:** High sulfur and phosphorus content preclude welding. * **Increased Cost:** Additional processing cost compared to as-rolled material. * **Scale Formation:** Produces oxide scale requiring removal before precision machining. --- **Summary:** AISI 1137 annealed at 790°C (1450°F) is a **process-optimized material condition** designed for **maximum manufacturability**. It represents a strategic investment in pre-processing to achieve unparalleled machinability and stability, thereby reducing total manufacturing cost and risk for complex, high-precision components. This condition is particularly valuable for parts that will be used in the as-machined state or will undergo case hardening, where a soft, uniform core is essential. -:- For detailed product information, please contact sales. -: AISI 1137 Steel, annealed at 790°C (1450°F) Specification Dimensions Size： Diameter 20-1000 mm Length <6129 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. -: AISI 1137 Steel, annealed at 790°C (1450°F) Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 1137 Steel Rod, annealed at 790°C (1450°F) -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 1137 Steel Rod, annealed at 790°C (1450°F) -:- For detailed product information, please contact sales. -:

Packing of AISI 1137 Steel Rod, annealed at 790°C (1450°F) -:- 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 Rod 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 2600 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