3J09 Elastic Alloy Bar
3J09 Elastic Alloy Bar is a precision elastic alloy round bar designed for springs, timer springs, watch springs, elastic sensing elements, frequency components, precision instruments, aerospace elastic parts and high-performance mechanical assemblies. 3J09 bar offers high elasticity, high strength, high hardness, non-magnetic performance and good dimensional stability for precision elastic applications.
SASA ALLOY supplies 3J09 elastic alloy bars, 3J09 round bars, 3J09 rods, forged bars and precision machined bar stock in customized diameter, length, tolerance and surface finish. MTC (Mill Test Certificate), EN 10204 3.1 certificate, PMI inspection, dimensional inspection, mechanical testing and third-party inspection can be provided according to project requirements.
Product Parameters
| Item | Details |
|---|---|
| Product Name | 3J09 Elastic Alloy Bar / 3J09 Round Bar / 3J9 Precision Elastic Alloy Rod |
| Grade | 3J09 / 3J9 |
| Material Type | Fe-Cr-Ni-Mo precision elastic alloy / spring alloy |
| Shape & Sizes | Round bar, rod, forged bar, machined bar; common diameter 6 mm – 200 mm, customized size available |
| Length | 1000 mm – 6000 mm, cut-to-length available according to customer drawing |
| Surface Finish | Black, bright, peeled, turned, polished, ground |
| Standards | GB/T 15002, GB/T 15001 or customer technical specification |
| Tolerance | Standard tolerance, h9, h11, k12 or customized tolerance according to drawing |
| Certificate | MTC, EN 10204 3.1 certificate, PMI report, dimensional inspection report, mechanical test report and third-party inspection available |
Chemical Composition
The following chemical composition is a typical reference range for 3J09 / 3J9 elastic alloy bar. Final chemical values should be confirmed according to the actual Mill Test Certificate.
| Element | Content (%) | Function in Alloy |
|---|---|---|
| Iron (Fe) | Balance | Base element for Fe-Cr-Ni-Mo elastic alloy structure |
| Chromium (Cr) | 19.0 – 20.5 | Improves corrosion resistance, oxidation resistance and strength |
| Nickel (Ni) | 9.0 – 10.5 | Supports toughness, stability and elastic performance |
| Molybdenum (Mo) | 1.60 – 1.85 | Improves strength, corrosion resistance and service stability |
| Carbon (C) | ≤ 0.12 | Controlled element affecting hardness, strength and processing performance |
| Manganese (Mn) | ≤ 2.00 | Controlled residual element and processing support |
| Silicon (Si) | ≤ 1.00 | Controlled residual element for processing and oxidation behavior |
| Phosphorus (P) | ≤ 0.030 | Controlled impurity for mechanical reliability |
| Sulfur (S) | ≤ 0.020 | Controlled impurity for clean structure and processing quality |
Mechanical Properties
3J09 is mainly selected for high elasticity, high strength, non-magnetic performance and precision spring stability. Mechanical properties may vary depending on bar diameter, cold working condition, solution treatment and aging condition.
| Property | Reference Value | Engineering Meaning |
|---|---|---|
| Material Type | Precision elastic alloy | Designed for elastic elements, springs and precision instrument parts |
| Tensile Strength | Condition dependent | Can be adjusted by cold working and heat treatment |
| Yield Strength | Condition dependent | Important for elastic recovery and spring force |
| Hardness | High after proper processing | Supports wear resistance and spring component stability |
| Elastic Performance | High elasticity | Suitable for springs, elastic sensing elements and frequency components |
| Magnetic Property | Non-magnetic or weak magnetic | Useful for precision instruments and sensitive assemblies |
| Dimensional Stability | Good after proper heat treatment | Important for timers, watches, sensors and aerospace elastic parts |
Common Size Table
| Diameter | Typical Length | Surface Finish | Common Use |
|---|---|---|---|
| 6 – 12 mm | 1000 – 3000 mm | Bright, polished, ground | Small spring pins, sensor shafts, precision instrument parts |
| 14 – 30 mm | 2000 – 6000 mm | Peeled, turned, bright | Elastic rods, timer parts, watch spring components |
| 32 – 60 mm | 3000 – 6000 mm | Black, peeled, rough turned | Machined elastic parts, instrument elements, aerospace components |
| 65 – 120 mm | Cut-to-length | Forged, rough turned, machined | Large precision elastic components and custom machined parts |
| Above 120 mm | Customized | Forged, rough machined | Special project components and customized precision assemblies |
Different Specifications Comparison
| Product Form | Main Feature | Recommended Application | Selection Advice |
|---|---|---|---|
| 3J09 Round Bar | Good balance of elastic performance and machinability | Precision springs, shafts, sensor parts, machined elastic elements | Recommended for standard bar machining and elastic component production |
| 3J09 Forged Bar | Suitable for larger sizes and heavy-duty elastic components | Aerospace elastic parts, large machined components | Recommended for large size and customized precision parts |
| 3J09 Bright Bar | Better surface finish and dimensional control | Precision instruments, medical device components, sensors | Recommended when tight tolerance and appearance are important |
| 3J09 Ground Bar | Smooth surface and improved size accuracy | CNC parts, precision shafts, elastic sensing components | Recommended for final machining allowance control |
| 3J09 Strip / Sheet | Suitable for spring plates, watch springs and timer springs | Watch spring, timer spring, diaphragm and frequency element production | Recommended when thin section or sheet geometry is required |
Equivalent Standards and International Names
| Standard / Name | Designation | Remarks |
|---|---|---|
| Chinese Grade | 3J09 | Precision elastic alloy grade |
| Alternative Grade | 3J9 | Common short designation in Chinese precision alloy system |
| Chemical Type | Fe-Cr-Ni-Mo alloy | Elastic alloy for precision instruments and spring components |
| Product Family | 3J Series Elastic Alloy | Includes 3J01, 3J09, 3J21 and 3J53 elastic alloys |
| Chinese Standard | GB/T 15002 / GB/T 15001 | Technical and inspection reference for precision elastic alloys |
| Related Grades | 3J01 / 3J21 / 3J53 | Selected according to elastic performance and application requirements |
| Common Product Forms | Bar, rod, wire, strip, sheet, plate | Different forms for spring, instrument and precision component production |
Production Process Flow
| Step | Process | Quality Control Focus |
|---|---|---|
| 1 | Raw Material Selection | Check Fe, Cr, Ni, Mo content, raw material source and heat number traceability |
| 2 | Melting / Refining | Control chromium, nickel, molybdenum and impurity elements |
| 3 | Ingot / Billet Preparation | Ensure suitable billet quality for rolling, forging or drawing |
| 4 | Hot Rolling / Forging | Control bar size, internal structure and deformation process |
| 5 | Solution Treatment | Improve plasticity and prepare material for later processing |
| 6 | Cold Working / Straightening | Adjust dimensional accuracy, strength and processing condition |
| 7 | Aging / Stress Relief | Develop elastic performance, dimensional stability and service reliability |
| 8 | Peeling / Turning / Grinding | Improve surface quality and dimensional tolerance |
| 9 | Inspection and Testing | PMI, chemical analysis, dimensional inspection, surface inspection and mechanical test if required |
| 10 | Packaging and Shipment | Protective wrapping, wooden case, label, heat number and shipping mark |
Product Inspection
| Inspection Item | Inspection Method | Purpose |
|---|---|---|
| Chemical Composition | Spectrometer analysis / laboratory test | Confirm 3J09 Fe-Cr-Ni-Mo alloy grade and element control |
| PMI Test | Positive Material Identification | Prevent material mix-up and wrong grade shipment |
| Mechanical Test | Tensile strength, yield strength, elongation, hardness or other required test | Verify mechanical performance according to order requirement |
| Elastic Performance Test | Customer-defined spring or elastic property test | Verify elastic performance for spring, timer and instrument applications |
| Dimension Inspection | Caliper, micrometer, straightness inspection | Confirm diameter, length, tolerance and straightness |
| Surface Inspection | Visual inspection and surface quality check | Check cracks, scratches, oxidation, peeling defects and surface finish |
| Ultrasonic Testing | UT inspection if required | Check internal defects for critical bars and forged sections |
| Certificate | MTC / EN 10204 3.1 / inspection report | Ensure material traceability and project documentation |
Product Packaging
| Packaging Item | Details | Benefit |
|---|---|---|
| Surface Protection | Plastic film, anti-rust paper, oil protection or protective wrapping | Protects bar surface from scratches and oxidation during transportation |
| Bundle Packing | Bars bundled with steel strips or protective belts | Prevents movement, bending and collision |
| Wooden Case / Wooden Pallet | Export-standard wooden case or pallet | Suitable for long-distance sea, air and truck shipment |
| Labeling | Grade, size, heat number, quantity, net weight and customer mark | Improves material traceability after delivery |
| Document Support | Packing list, invoice, MTC, EN 10204 3.1 certificate and inspection report if required | Supports customs clearance and project acceptance |
Applications & Machinability
Applications
| Industry | Typical Parts | Why 3J09 Bar Is Used |
|---|---|---|
| Medical Instruments | Precision spring parts, elastic sensing elements, instrument components | Stable elastic behavior and non-magnetic performance for precision functional parts |
| Aerospace | Elastic elements, springs, timer parts, control system components | High strength and elastic stability support reliable service in precision assemblies |
| Marine Hardware | Elastic pins, spring elements, sensor assemblies and control parts | Can be used where elastic performance and moderate corrosion resistance are required; surface protection should be considered |
| Chemical Processing | Instrument elastic parts, sensor components, control device parts | Suitable for precision elastic function parts; corrosion environment should be evaluated before material selection |
| Instrumentation & Timing Devices | Watch springs, timer springs, elastic rods, measuring elements and frequency components | High elasticity and dimensional stability make it suitable for precision timing and instrument devices |
Machinability, Welding and Heat Treatment
| Processing Property | Performance | Recommendation |
|---|---|---|
| Machinability | Machinable after proper treatment; not a free-cutting alloy like 303 stainless steel | Use rigid machines, sharp carbide tools, suitable cutting speed and sufficient coolant |
| Forming Performance | Suitable for spring and elastic component processing under proper condition | Forming should be planned according to final hardness and heat treatment requirement |
| Welding Performance | Welding is possible with proper procedure, but elastic performance and heat-affected zone should be considered | Confirm welding procedure, heat treatment and final elastic property requirement before fabrication |
| Heat Treatment | Solution treatment, aging or stress relief may be used to adjust final performance | Final heat treatment should follow mechanical property target and project specification |
| Cold Working | Cold working can affect mechanical and elastic properties | Final aging or stress-relief treatment may be required after forming or machining |
| Surface Protection | Surface oxidation may occur during storage and transportation | Use oil protection, dry storage and export protective packaging |
Why Choose SAKY STEEL?
| Advantage | Description |
|---|---|
| Professional Precision Alloy Supply | SAKY STEEL supplies precision alloys including 3J09, 3J01, 3J21, 3J53, 1J soft magnetic alloys, 2J permanent magnetic alloys, 4J expansion alloys and 6J resistance alloys for industrial and high-performance applications. |
| Customized Size Capability | Diameter, length, surface finish, tolerance, cutting service and machining allowance can be customized according to customer drawings or project requirements. |
| Quality Control and Traceability | Material traceability, heat number control, PMI testing, dimensional inspection, surface inspection, mechanical testing and elastic property testing can be arranged. |
| Certificate Support | We can provide MTC (Mill Test Certificate / 质保书), EN 10204 3.1 certificate, PMI report, inspection report and other quality documents according to order requirements. |
| Export Packaging Experience | Export wooden cases, wooden pallets, protective wrapping, oil protection and clear labels help ensure safe delivery for international shipments. |
| Technical Service Support | Our team can support grade selection, equivalent standard checking, heat treatment discussion, elastic property requirement confirmation and technical document preparation before shipment. |
FAQ
Q1: What is 3J09 Bar?
3J09 Bar is a precision elastic alloy bar used for springs, timer springs, watch springs, elastic sensing elements, frequency components, precision instruments and mechanical elastic assemblies.
Q2: Is 3J09 the same as 3J9?
Yes, 3J09 is also commonly written as 3J9 in some material references. Before ordering, customers should confirm the required grade, chemical composition, heat treatment condition and product form.
Q3: What is the main feature of 3J09 elastic alloy?
3J09 offers high elasticity, high strength, high hardness, non-magnetic or weak magnetic behavior and good stability. It is suitable for precision elastic components and spring applications.
Q4: Can SASA ALLOY provide 3J09 Bar with MTC?
Yes. SASA ALLOY can provide MTC (Mill Test Certificate / 质保书), EN 10204 3.1 certificate, PMI report, dimensional inspection report, mechanical test report and third-party inspection documents according to customer requirements.
Q5: What sizes of 3J09 Bar are available?
Common diameters include 6 mm to 200 mm. Length, tolerance and surface finish can be customized. Cut-to-length service is available for precision machining and spring component production.
Q6: Is 3J09 easy to machine?
3J09 is machinable, but it is not a free-cutting alloy like 303 stainless steel. Rigid equipment, sharp carbide tools, suitable cutting speed and sufficient coolant are recommended.
Q7: Can 3J09 be welded?
Welding may be possible with proper procedure, but heat input and final elastic properties should be considered. For critical spring or elastic parts, customers should confirm welding and post-weld heat treatment before fabrication.
Q8: Does 3J09 require heat treatment?
Heat treatment, aging or stress relief may be required to achieve the required strength, hardness and elastic performance. The final process should be selected according to project specifications and mechanical property targets.
Q9: What applications use 3J09 Bar?
3J09 Bar is used in watch springs, timer springs, precision springs, elastic sensing elements, frequency components, instrument parts, aerospace elastic components and precision machinery.
Q10: How can I get a quotation for 3J09 Bar?
Please send your required grade, diameter, length, quantity, surface finish, tolerance, heat treatment condition, mechanical property requirement and certificate requirements to SASA ALLOY. Our team will check availability, production route, delivery time and price for your project.
