AISI 5160H Steel Capillary

AISI 5160H Steel Capillary, annealed, 25 mm (1 in.) round Product Information -:- For detailed product information, please contact sales. -: AISI 5160H Steel Capillary, annealed, 25 mm (1 in.) round Synonyms -:- For detailed product information, please contact sales. -:

AISI 5160H Steel, annealed, 25 mm (1 in.) round Product Information -:- For detailed product information, please contact sales. -: # **AISI 5160H Steel, Annealed, 25 mm (1 inch) Round Bar - Technical Data Sheet** ## **1. Product Overview** **AISI 5160H annealed 25 mm (1 inch) round bar** is a **hardenability-controlled, high-carbon chromium spring steel** supplied in a fully softened condition with guaranteed response to subsequent heat treatment. The "H" designation indicates the steel is chemically controlled within strict SAE J1268 limits, ensuring predictable hardenability across all production lots. This specific product form—**1 inch diameter round bar in annealed condition**—provides manufacturers with exceptional consistency in both machining performance and final heat treatment results, particularly crucial for spring applications and high-stress components requiring reliable fatigue resistance. The 25mm diameter represents an **optimal manufacturing size** that balances sufficient cross-section for structural applications with excellent heat treatment uniformity. This combination of controlled chemistry, optimal section size, and standardized annealing produces a material ideally suited for high-volume production of critical spring components and high-stress parts where both machining efficiency and final property consistency are paramount. --- ## **2. Chemical Composition (SAE J404/J412 with H-Grade Controls)** | Element | Composition Range (%) | H-Grade Control Significance for 25mm Annealed Bar | |---------|----------------------|---------------------------------------------------| | **Carbon (C)** | 0.55 - 0.62 | Tightly controlled (±0.035% from nominal) for consistent hardenability and spring properties | | **Manganese (Mn)** | 0.75 - 1.00 | Optimized range ensures predictable transformation during annealing and hardening | | **Phosphorus (P)** | ≤ 0.030 | Reduced maximum for improved impact toughness in annealed and hardened states | | **Sulfur (S)** | ≤ 0.035 | Controlled for optimal machinability without compromising transverse properties | | **Silicon (Si)** | 0.15 - 0.35 | Controlled to minimize variation in hardenability response | | **Chromium (Cr)** | 0.70 - 0.95 | Primary alloying element with optimized range for maximum consistency | | **Iron (Fe)** | Balance | Base matrix with controlled residual elements for predictable annealing | **Product Specifications:** - **SAE/AISI:** 5160H - **UNS:** G51601 - **Form:** Round bar, annealed condition - **Diameter:** 25.0 mm ±0.4 mm (1.00 inch ±0.016 inch) - tighter tolerance than standard - **Hardenability Standard:** SAE J1268 compliance certified - **Standard Lengths:** 3m or 6m; precision cut lengths available - **Surface Condition:** Annealed finish with controlled decarburization --- ## **3. Hardenability Characteristics (SAE J1268)** ### **Guaranteed Hardenability Bands:** *These bands apply after proper hardening; annealing provides optimal starting condition* | Distance from Quenched End (1/16") | Minimum HRC | Maximum HRC | Typical Production Range for 25mm Section | |------------------------------------|-------------|-------------|-------------------------------------------| | **J1 (1.5mm)** | 52 | 62 | 56-60 HRC | | **J4 (6.4mm)** | 48 | 58 | 52-56 HRC | | **J7 (11.1mm)** | 44 | 54 | 48-52 HRC | | **J10 (15.9mm)** | 39 | 49 | 43-47 HRC | | **J14 (22.2mm)** | 35 | 45 | 39-43 HRC | | **J20 (31.8mm)** | 30 | 40 | 34-38 HRC | | **J30 (47.6mm)** | 26 | 36 | 30-34 HRC | ### **Critical Diameter Data for 25mm Round:** - **Ideal Critical Diameter (D₁) in oil:** 85-100 mm - **95% Martensite (D₉₅):** 75-90 mm - **Hardness at 25mm diameter center after oil quench:** 47-52 HRC (as-quenched) - **Hardness uniformity in 25mm round:** ≤2.5 HRC variation surface to center - **Jominy equivalent for 25mm round center:** ~J9-J13 position ### **25mm Section Advantage for H-Grade Material:** 1. **Optimal realization** of hardenability potential 2. **Predictable property gradients** enabling accurate spring design 3. **Consistent response** due to thermal mass optimization 4. **Minimal banding effects** in final hardened state --- ## **4. Physical & Mechanical Properties (As-Annealed, 25mm Round)** ### **Typical As-Annealed Properties:** - **Hardness:** 174-217 HB (85-95 HRB) - **Tensile Strength:** 585-760 MPa (85-110 ksi) - **Yield Strength (0.2% offset):** 345-515 MPa (50-75 ksi) - **Elongation (in 50mm/2"):** 20-28% - **Reduction of Area:** 45-58% - **Modulus of Elasticity:** 205 GPa (29,700 ksi) - **Shear Modulus:** 80 GPa (11,600 ksi) ### **Machinability Characteristics (25mm Round):** - **Machinability Rating:** 50-55% (relative to 1212 steel = 100%) - **Optimal Cutting Parameters:** - Turning: 45-65 m/min (150-215 SFM) with carbide - Feed: 0.15-0.35 mm/rev (0.006-0.014 in/rev) - Tool life: 20-40% longer than standard 5160 annealed - **Chip Formation:** Consistent, manageable chips - **Surface Finish:** 1.6-3.2 μm Ra (63-125 μin) readily achievable - **Dimensional Stability:** Excellent due to stress-free annealed condition ### **Physical Properties:** - **Weight per meter:** 3.85 kg/m (2.59 lb/ft) - **Cross-sectional Area:** 490.9 mm² (0.761 in²) - **Surface Area per meter:** 0.0785 m²/m (0.258 ft²/ft) - **Density:** 7.85 g/cm³ (0.284 lb/in³) - **Thermal Conductivity:** 42.0 W/m·K at 100°C - **Coefficient of Thermal Expansion:** 12.3 μm/m·°C (20-100°C) - **Specific Heat:** 460 J/kg·K at 20°C ### **Property Uniformity in 25mm Round:** | Property | Surface | Mid-radius | Center | Maximum Variation | |----------|---------|------------|--------|-------------------| | **Hardness (HB)** | 195 ±7 | 198 ±5 | 200 ±7 | ≤5 HB (2.5%) | | **Microstructure** | Fine pearlite | Uniform pearlite | Slightly coarser | Consistent phase distribution | | **Decarb Depth** | 0.10-0.20mm | N/A | N/A | Controlled ≤0.20mm | | **Grain Size** | ASTM 6-7 | ASTM 6-7 | ASTM 5-6 | Uniform refinement | --- ## **5. Annealing Process & Metallurgical Structure** ### **Standard Annealing Parameters for 5160H 25mm Round:** - **Temperature:** 795-815°C (1465-1500°F) - **Soak Time:** 1.5-2.5 hours at temperature - **Cooling Rate:** Furnace cool to 600°C at 20-30°C/hour, then air cool - **Atmosphere:** Protective (endothermic or nitrogen-based) with decarb control - **Decarburization Control:** ≤0.20mm total depth specified for spring applications ### **Resulting Microstructure Characteristics:** - **Primary Structure:** Coarse lamellar pearlite (65-80%) - **Secondary Structure:** Proeutectoid ferrite at grain boundaries - **Carbide Morphology:** - Lamellar spacing: 0.5-1.0 μm - Partial spheroidization: 10-30% depending on cooling rate - Uniform distribution throughout cross-section - **Grain Size:** ASTM 6-8 (consistent throughout 25mm diameter) - **Prior Austenite Grain Size:** ASTM 5-7 (critical for subsequent hardening consistency) ### **Benefits of Controlled Annealing for 5160H:** 1. **Consistent machinability** across all production lots 2. **Predictable dimensional changes** during subsequent heat treatment 3. **Minimal residual stresses** for improved machining accuracy 4. **Uniform carbide distribution** for optimal hardening response 5. **Reduced banding** compared to standard material 6. **Optimized structure** for spring applications after hardening --- ## **6. Manufacturing & Processing Guidelines** ### **Recommended Machining Parameters:** | Operation | Speed (m/min) | Feed (mm/rev) | Depth of Cut (mm) | Tool Recommendation | |-----------|---------------|---------------|-------------------|---------------------| | **Turning** | 45-65 | 0.20-0.40 | Up to 5.0 | Carbide, C2-C4, positive rake | | **Drilling** | 25-40 | 0.15-0.30 | Full diameter | HSS-Co, 118-135° point | | **Milling** | 40-60 | 0.10-0.25 per tooth | Up to 4.0 | Carbide, 4-6 flutes | | **Tapping** | 8-18 | Pitch determined | Full depth | HSS, spiral point/flute | | **Threading** | 20-40 | Pitch dependent | Full depth | Carbide inserts | ### **Forming & Fabrication:** - **Cold Bending:** Minimum radius = 1.5× diameter (37.5mm) for 90° bends - **Hot Forging:** Excellent at 1050-850°C; finish forging ≥850°C - **Spring Coiling:** Performed in annealed state, then heat treated - **Thread Rolling:** Excellent results; predictable material flow - **Welding:** Not recommended in annealed condition if final properties required ### **Subsequent Heat Treatment (Typical for 25mm Round):** 1. **Preheat:** 650-700°C (1200-1290°F) 2. **Austenitize:** 845-865°C (1555-1590°F) 3. **Quench:** Fast oil (ISO VG 68-100), moderate agitation 4. **Temper:** 425-550°C (800-1020°F) depending on required hardness 5. **Expected Results for Spring Applications:** - Surface hardness: 46-52 HRC - Center hardness: 45-51 HRC - Hardness gradient: ≤2.5 HRC surface to center - Spring properties: Consistent modulus and fatigue resistance ### **Spring-Specific Processing:** - **Coiling:** Perform in annealed condition with proper mandrel design - **Stress Relieving:** 400-450°C after coiling, before hardening - **Shot Peening:** Mandatory for fatigue life improvement - **Presetting:** Required for compression springs to prevent set - **Surface Protection:** Phosphating or coating for corrosion resistance --- ## **7. Product Applications** ### **High-Volume Spring Applications:** - **Automotive suspension** coil springs (critical for ride consistency) - **Valve springs** for internal combustion engines - **Clutch springs** and transmission spring components - **Industrial machinery** springs requiring predictable performance - **Agricultural equipment** springs and suspension components ### **Automotive Components (High-Stress Applications):** - **Stabilizer bars** and torsion bars requiring consistent properties - **Axle shafts** for performance vehicles - **Steering components** requiring fatigue resistance - **Suspension arms** and linkage components - **High-stress fasteners** and studs ### **Industrial Power Transmission:** - **Heavy-duty gear blanks** for predictable hardening - **Spline shafts** requiring uniform properties - **Coupling components** with consistent torque capacity - **Machine tool spindles** requiring dimensional stability - **Pump shafts** for hydraulic systems ### **Critical Applications Requiring Certification:** - **Aerospace components** (non-flight critical springs) - **Defense system parts** requiring material traceability - **Medical equipment** components needing predictable performance - **Precision instrumentation** springs and components - **Safety-critical springs** in industrial equipment ### **Why Specify 5160H 25mm Annealed Round:** 1. **High-volume spring production** where consistency is critical 2. **Safety-critical applications** requiring predictable fatigue life 3. **Statistical process control** manufacturing environments 4. **Applications** requiring material certification and traceability 5. **Components** where heat treatment distortion must be minimized 6. **Production** with just-in-time delivery requirements 7. **Applications** where reduced safety margins enable design optimization --- ## **8. International Standards & Equivalents** ### **Primary Standards:** | Standard | Designation | Specification | |----------|-------------|---------------| | **SAE/AISI** | **5160H** | SAE J404, J412, J1268 | | **ASTM** | **A304** | Standard Specification for H-Steel Bars | | **ASTM** | **A689** | Specification for Carbon and Alloy Steel Bars for Springs | | **AMS** | **AMS 6440** | Aircraft quality steel (special applications) | ### **Global H-Grade Equivalents:** | Country/Region | Standard | H-Grade Equivalent | Similar Product Form | |----------------|----------|-------------------|----------------------| | **International (ISO)** | ISO 683-14 | **60Cr4H** | Spring steel, annealed condition | | **Europe (EN)** | EN 10089 | **60Cr4H** | Designation 1.7102H | | **Germany** | DIN 17221 | **60Cr4H** | Federstahl, weichgeglüht | | **Japan** | JIS G4801 | **SUP6H** | Spring steel, annealed | | **China** | GB/T 1222 | **60Si2CrAH** | Spring steel, annealed | | **United Kingdom** | BS 970 | **525H60H** | Spring steel, softened condition | | **France** | NF A35-571 | **60SC7H** | Acier pour ressorts | ### **Spring-Specific Standards:** - **SAE J1320:** Physical and Chemical Properties of Spring Steels - **ISO 8458:** Mechanical spring wire - Technical delivery conditions - **DIN 17223:** Patented cold drawn unalloyed spring steel wire - **ASTM A125:** Standard Specification for Steel Springs, Helical, Heat Treated ### **Dimensional Standards for 25mm H-Grade Round Bar:** - **Diameter Tolerance:** Typically h10 or ±0.10mm for precision applications - **Straightness:** ≤0.5mm per meter for spring quality bars - **Out-of-Roundness:** ≤0.2mm for precision ground bars - **Surface Quality:** Controlled scale or machined finish available - **Length Tolerance:** ±2mm for precision cut lengths --- ## **9. Quality Control & Certification** ### **Mandatory Certification Requirements:** 1. **Hardenability Certificate:** Jominy curve showing compliance with SAE J1268 bands 2. **Chemical Analysis:** Full elemental analysis per heat with traceability 3. **Annealing Record:** Complete thermal cycle documentation 4. **Mechanical Properties:** Tensile and hardness data from representative samples 5. **Microstructural Evaluation:** Grain size and decarburization assessment ### **Spring-Specific Quality Requirements:** - **Decarburization Control:** ≤0.20mm total depth (critical for fatigue resistance) - **Surface Quality:** Free from seams, laps, and inclusions - **Grain Size Consistency:** ASTM 6-8 throughout cross-section - **Hardness Uniformity:** ≤10 HB range within same bar - **Straightness:** ≤0.5mm per meter for coiling operations ### **Statistical Quality Requirements:** - **Hardenability Compliance:** 100% of heats within SAE J1268 bands - **Process Capability:** Cpk ≥ 1.67 for all critical characteristics - **Lot-to-Lot Consistency:** ≤8 HB variation in annealed condition - **Diameter Control:** ≤0.08mm variation along bar length - **Traceability:** Complete from melt to finished annealed bar ### **Incoming Inspection Protocol:** 1. Verify certification against material markings and heat numbers 2. Check hardness at multiple positions (minimum 3 per bar) 3. Measure diameter at minimum 3 positions along length 4. Inspect surface quality for defects or excessive scale 5. Perform sample machining test for production validation 6. Verify decarburization depth if critical for application 7. Check straightness for spring coiling applications --- ## **10. Technical & Economic Advantages** ### **Technical Advantages:** ✅ **Predictable spring properties** after heat treatment ✅ **Guaranteed hardening response** enabling reduced safety factors ✅ **Excellent fatigue resistance** with consistent material properties ✅ **Superior dimensional stability** during machining operations ✅ **Consistent coiling characteristics** for spring manufacturing ✅ **Reduced heat treatment distortion** from uniform starting condition ✅ **Minimal property variation** in high-volume production ### **Economic Benefits:** ✅ **Reduced inspection costs** through material certification ✅ **Lower scrap rates** from predictable material behavior ✅ **Extended tool life** reduces tooling costs ✅ **Faster machining cycles** from optimized parameters ✅ **Reduced safety stock** requirements due to consistency ✅ **Improved spring performance** reduces warranty claims ✅ **Higher production yield** from consistent heat treatment response ### **Cost-Benefit Analysis for 25mm 5160H:** | Cost Factor | 5160H vs. Standard 5160 | Justification | |-------------|-------------------------|---------------| | **Material Premium** | +25-35% | H-grade certification and tighter controls | | **Machining Savings** | -20-35% | Consistent performance reduces variables | | **Tooling Cost** | -15-30% | Extended tool life from uniform hardness | | **Inspection Cost** | -40-60% | Reduced frequency due to certification | | **Scrap Reduction** | -25-45% | Predictable behavior minimizes errors | | **Spring Performance** | +15-25% | Consistent properties improve reliability | | **Total Cost Impact** | **10-20% lower in production** | **Positive ROI for volume applications** | ### **Spring Manufacturing Specific Benefits:** 1. **Consistent spring rates** within production lots 2. **Predictable set characteristics** after presetting 3. **Uniform fatigue life** across production batches 4. **Reduced sorting and testing** of finished springs 5. **Optimized heat treatment cycles** from consistent starting condition --- ## **11. Design & Engineering Considerations** ### **Spring Design Parameters (After Heat Treatment):** - **Shear Modulus (G):** 79-81 GPa (tempered at 425-475°C) - **Modulus of Elasticity (E):** 205-207 GPa - **Fatigue Endurance Limit:** 450-550 MPa (polished, R=-1) - **Shot Peening Benefit:** Increases fatigue limit by 30-50% - **Design Stress Levels:** Typically 60-70% of tensile strength ### **Optimal Application Parameters for 25mm 5160H:** - **Production Volume:** >1000 pieces annually to justify H-grade premium - **Component Criticality:** Safety-critical or high-reliability applications - **Tolerance Requirements:** Applications needing ±0.025mm dimensional control - **Fatigue Requirements:** Components with cyclic loading >10⁵ cycles - **Quality Systems:** Manufacturing environments with statistical process control ### **Spring Design Recommendations:** 1. **Stress Calculations:** Use minimum guaranteed properties for conservative design 2. **Surface Finish:** Specify 0.8-1.6 μm Ra for optimal fatigue resistance 3. **Shot Peening:** Mandatory for all dynamic spring applications 4. **Presetting:** Required for compression springs to prevent permanent set 5. **Corrosion Protection:** Essential for springs in corrosive environments ### **Processing Sequence Optimization:** 1. **Coiling:** Perform in annealed state with controlled feed rates 2. **Stress Relieving:** 400-450°C after coiling, before hardening 3. **Hardening:** Oil quench from 845-865°C 4. **Tempering:** 425-475°C for optimal spring properties 5. **Shot Peening:** Almen intensity 0.008-0.012A 6. **Presetting:** To initial operating position 7. **Testing:** Sample testing for load-deflection characteristics 8. **Surface Treatment:** Phosphating or coating for corrosion protection --- ## **12. Storage, Handling & Traceability** ### **Material Identification & Packaging:** - **Heat Number:** Permanently marked on each bar or bundle - **Hardenability Code:** Identification of Jominy band position - **Certification:** EN 10204 3.1 or 3.2 certificate with each shipment - **Packaging:** VCI wrapping or rust preventive coating for spring steel - **Labeling:** Clear identification of material, size, and spring grade ### **Storage & Handling Requirements:** - **Storage Environment:** Controlled humidity (RH < 60%), temperature stable - **Stacking:** Properly supported on racks; maximum stack height 1.2m - **Handling Equipment:** Non-marring nylon slings or protective magnetic lifters - **Shelf Life:** 12 months with proper protection; quarterly inspection recommended - **Revalidation:** Required if stored >12 months or exposed to adverse conditions ### **Traceability System for Spring Applications:** 1. **Material Origin:** Melt practice, heat number, ladle analysis 2. **Processing History:** Hot working, annealing parameters, testing results 3. **Spring Manufacturing Data:** Coiling parameters, heat treatment records 4. **Performance Data:** Spring rate, fatigue test results, failure analysis 5. **Certification Chain:** Complete documentation from mill to end user 6. **Application History:** Service conditions and performance feedback ### **Quality Documentation Requirements:** - **Material Certificates:** Full chemical and mechanical properties - **Process Records:** All thermal and mechanical processing steps - **Test Reports:** Dimensional, mechanical, and metallurgical testing - **Statistical Data:** Process capability indices for critical characteristics - **Compliance Statements:** REACH, RoHS, and industry-specific requirements --- **Technical Significance:** AISI 5160H in 25mm annealed round bar form represents the highest level of material control for spring and high-stress applications. The H-grade certification combined with optimal section size provides unprecedented consistency in both manufacturing processes and final performance characteristics. For spring applications particularly, this consistency translates directly into predictable spring rates, uniform fatigue life, and reliable performance in service. The additional cost of H-grade material is typically justified through reduced inspection requirements, improved production yields, and enhanced product reliability—especially valuable in high-volume manufacturing and safety-critical applications. **Revision:** 1.1 **Date:** October 2023 **Disclaimer:** This technical data describes AISI 5160H material annealed under controlled conditions. Actual properties may vary based on specific annealing cycle parameters and cooling rates. The H-grade certification ensures hardenability consistency but proper heat treatment after forming is essential to realize the guaranteed properties. Always consult with material suppliers for application-specific recommendations and conduct appropriate testing for critical applications. Spring design requires specialized engineering expertise; consult with spring design specialists for optimal component design. The benefits of H-grade material are maximized when combined with statistical process control in manufacturing. -:- For detailed product information, please contact sales. -: AISI 5160H Steel, annealed, 25 mm (1 in.) round Specification Dimensions Size： Diameter 20-1000 mm Length <4130 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 5160H Steel, annealed, 25 mm (1 in.) round Properties -:- For detailed product information, please contact sales. -:

Applications of AISI 5160H Steel Capillary, annealed, 25 mm (1 in.) round -:- For detailed product information, please contact sales. -: Chemical Identifiers AISI 5160H Steel Capillary, annealed, 25 mm (1 in.) round -:- For detailed product information, please contact sales. -:

Packing of AISI 5160H Steel Capillary, annealed, 25 mm (1 in.) round -:- 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 Capillary 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 601 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