3J21 Elastic Alloy Bar
3J21 Elastic Alloy Bar is a cobalt-chromium-nickel-molybdenum precision elastic alloy bar designed for high strength, high elasticity, fatigue resistance, corrosion resistance and non-magnetic performance. It is also widely known as Elgiloy Bar, Phynox Bar, UNS R30003 Bar, Co40CrNiMo Bar and Nivaflex-type elastic alloy bar.
SASA ALLOY supplies 3J21 elastic alloy bars, 3J21 round bars, 3J21 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, corrosion-related inspection and third-party inspection can be provided according to project requirements.
Product Parameters
| Item | Details |
|---|---|
| Product Name | 3J21 Elastic Alloy Bar / Elgiloy Bar / Phynox Bar / UNS R30003 Bar |
| Grade | 3J21 / UNS R30003 / Elgiloy / Phynox / Co40CrNiMo |
| Material Type | Cobalt-Chromium-Nickel-Molybdenum precision elastic 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 | ASTM F1058, AMS 5833, ISO 5832-7, GB/T 15002, GB/T 15001 or customer 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 3J21 / Elgiloy / Phynox / UNS R30003 elastic alloy bar. Final chemical values should be confirmed according to the actual Mill Test Certificate.
| Element | Content (%) | Function in Alloy |
|---|---|---|
| Cobalt (Co) | 39.0 – 41.0 | Base element providing strength, fatigue resistance and elastic performance |
| Chromium (Cr) | 19.0 – 21.0 | Improves corrosion resistance, oxidation resistance and surface stability |
| Nickel (Ni) | 14.0 – 16.0 | Supports toughness, ductility and austenitic structure stability |
| Molybdenum (Mo) | 6.0 – 8.0 | Enhances corrosion resistance, strength and service reliability |
| Iron (Fe) | Balance | Supports alloy structure and processing performance |
| Manganese (Mn) | 1.5 – 2.5 | Supports processing and alloy stability |
| Carbon (C) | ≤ 0.15 | Controlled element affecting hardness and mechanical properties |
| Beryllium (Be) | ≤ 0.01 | Controlled minor element according to specification |
| Silicon (Si) | ≤ 1.20 | Controlled residual element for processing and oxidation behavior |
| Phosphorus (P) | ≤ 0.015 | Controlled impurity for mechanical reliability |
| Sulfur (S) | ≤ 0.015 | Controlled impurity for clean structure and processing quality |
Mechanical Properties
3J21 bar is mainly selected for high elasticity, high fatigue life, high strength, corrosion resistance and non-magnetic performance. Mechanical properties depend on diameter, cold work, heat treatment condition and final aging process.
| Property | Reference Value | Engineering Meaning |
|---|---|---|
| Material Type | Cobalt-based precision elastic alloy | Suitable for springs, elastic parts and corrosion-resistant components |
| Tensile Strength | Condition dependent | Can reach high strength after cold working and aging |
| Yield Strength | Condition dependent | Important for elastic recovery and spring force |
| Hardness | High after proper aging | Supports wear resistance and long-term component stability |
| Fatigue Resistance | Excellent | Useful for springs, valve parts and cyclic-load components |
| Corrosion Resistance | Excellent in many media | Suitable for medical, marine and chemical processing environments |
| Magnetic Property | Non-magnetic | Suitable for sensitive instruments and magnetic-field-related applications |
| Working Temperature | Application dependent | Often selected for stable elastic performance and low relaxation service |
Common Size Table
| Diameter | Typical Length | Surface Finish | Common Use |
|---|---|---|---|
| 6 – 12 mm | 1000 – 3000 mm | Bright, polished, ground | Small springs, medical instrument parts, precision sensor pins |
| 14 – 30 mm | 2000 – 6000 mm | Peeled, turned, bright | Elastic rods, valve springs, aerospace elastic components |
| 32 – 60 mm | 3000 – 6000 mm | Black, peeled, rough turned | Machined elastic parts, corrosion-resistant spring 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 elastic assemblies |
Different Specifications Comparison
| Product Form | Main Feature | Recommended Application | Selection Advice |
|---|---|---|---|
| 3J21 Round Bar | Good balance of elastic performance, corrosion resistance and machinability | Precision springs, shafts, sensors, medical and aerospace elastic parts | Recommended for standard bar machining and elastic component production |
| 3J21 Forged Bar | Suitable for larger sizes and heavy-duty elastic components | Large valve components, aerospace elastic parts, corrosion-resistant machinery | Recommended for large size and customized precision parts |
| 3J21 Bright Bar | Better surface finish and dimensional control | Medical instruments, precision instruments, sensors and small parts | Recommended when tight tolerance and surface quality are important |
| 3J21 Ground Bar | Smooth surface and improved size accuracy | CNC parts, precision shafts, elastic sensing components | Recommended for final machining allowance control |
| 3J21 Strip / Wire | Suitable for springs, diaphragms and small elastic parts | Medical springs, valve springs, watch springs, diaphragms | Recommended when wire or strip geometry is required |
Equivalent Standards and International Names
| Standard / Name | Designation | Remarks |
|---|---|---|
| Chinese Grade | 3J21 | Precision elastic alloy grade |
| UNS Number | UNS R30003 | Common international designation for Elgiloy-type alloy |
| Common Trade Name | Elgiloy / Phynox | Widely used names in medical, aerospace and spring applications |
| Alternative Name | Co40CrNiMo / Nivaflex Type Alloy | Indicates cobalt-chromium-nickel-molybdenum alloy system |
| International Standard | ASTM F1058 / ISO 5832-7 | Common reference for wrought cobalt-chromium-nickel-molybdenum alloy |
| Aerospace Reference | AMS 5833 | Used for wire and spring-related aerospace applications |
| Product Family | 3J Series Elastic Alloy | Includes 3J01, 3J09, 3J21 and 3J53 elastic alloys |
| Common Product Forms | Bar, rod, wire, strip, sheet, plate | Different forms for spring, medical, aerospace and precision components |
Production Process Flow
| Step | Process | Quality Control Focus |
|---|---|---|
| 1 | Raw Material Selection | Check Co, Cr, Ni, Mo content, raw material source and heat number traceability |
| 2 | Melting / Refining | Control cobalt, 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 ductility and prepare material for later processing |
| 6 | Cold Working / Straightening | Increase strength and adjust dimensional accuracy before aging |
| 7 | Aging / Stress Relief | Develop high elastic performance, fatigue resistance and dimensional stability |
| 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 3J21 Co-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, fatigue or elastic property test | Verify elastic performance for spring, medical and aerospace applications |
| Corrosion-Related Inspection | Customer-defined corrosion test if required | Support medical, marine and chemical processing 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 3J21 Bar Is Used |
|---|---|---|
| Medical Instruments | Medical springs, instrument springs, surgical device parts, precision elastic components | Non-magnetic performance, high fatigue resistance and good corrosion resistance for precision medical applications |
| Aerospace | Aerospace springs, elastic elements, control system parts, fast response components | High strength, fatigue life and elastic stability support reliable service in demanding assemblies |
| Marine Hardware | Corrosion-resistant springs, valve parts, elastic pins, sensor assemblies | Excellent corrosion resistance and fatigue resistance make it suitable for harsh marine environments |
| Chemical Processing | Valve springs, pump spring parts, corrosion-resistant elastic components, instrument parts | Good corrosion resistance in many media and reliable elastic performance for chemical equipment |
| Instrumentation & Precision Machinery | Diaphragms, sensors, springs, elastic rods, measuring elements and precision assemblies | High elasticity, non-magnetic behavior and dimensional stability make it suitable for precision devices |
Machinability, Welding and Heat Treatment
| Processing Property | Performance | Recommendation |
|---|---|---|
| Machinability | Machinable but more difficult than common stainless steel; not a free-cutting alloy like 303 stainless steel | Use rigid machines, sharp carbide tools, suitable cutting speed and sufficient coolant |
| Forming Performance | Good ductility in proper condition; forming should be done before final aging when possible | Plan forming, cold working and aging process together for final elastic properties |
| Welding Performance | Welding is possible with proper procedure, but final mechanical and elastic properties should be considered | Confirm welding procedure, heat treatment and final performance requirements before fabrication |
| Heat Treatment | Cold work and aging treatment are important for final strength and elastic performance | Final heat treatment should follow mechanical property target and project specification |
| Cold Working | Cold working can increase strength and help develop final performance after aging | Additional strength can be obtained from aging after suitable cold reduction |
| Surface Protection | Surface protection is recommended during storage and transportation | Use protective wrapping, dry storage and export packaging to avoid surface damage |
Why Choose SAKY STEEL?
| Advantage | Description |
|---|---|
| Professional Precision Alloy Supply | SAKY STEEL supplies precision alloys including 3J21, 3J01, 3J09, 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, corrosion-related inspection 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 3J21 Bar?
3J21 Bar is a cobalt-chromium-nickel-molybdenum precision elastic alloy bar. It is also known as Elgiloy Bar, Phynox Bar, UNS R30003 Bar and Co40CrNiMo Bar. It is used for springs, elastic parts, medical instruments, aerospace components, marine hardware and chemical processing parts.
Q2: Is 3J21 the same as Elgiloy or Phynox?
3J21 is commonly associated with Elgiloy, Phynox and UNS R30003 material references. Before ordering, customers should confirm the required grade, chemical composition, standard, heat treatment condition and product form.
Q3: What is the main feature of 3J21 elastic alloy?
3J21 offers high elasticity, high strength, excellent fatigue resistance, good corrosion resistance and non-magnetic performance. It is suitable for precision spring and elastic component applications.
Q4: Can SASA ALLOY provide 3J21 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 3J21 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 3J21 easy to machine?
3J21 is machinable, but it is more difficult to machine than common stainless steel and is not a free-cutting alloy like 303 stainless steel. Rigid equipment, sharp carbide tools, proper cutting speed and sufficient coolant are recommended.
Q7: Can 3J21 be welded?
Welding may be possible with proper procedure, but heat input and final mechanical or elastic properties should be considered. For critical spring or elastic parts, customers should confirm welding and post-weld heat treatment before fabrication.
Q8: Does 3J21 require heat treatment?
Yes. Cold working and aging treatment are commonly used to obtain high strength and elastic performance. Final heat treatment should be selected according to project specifications and mechanical property targets.
Q9: What applications use 3J21 Bar?
3J21 Bar is used in medical springs, surgical device parts, aerospace springs, valve springs, diaphragms, sensors, marine hardware, chemical processing components and corrosion-resistant precision elastic assemblies.
Q10: How can I get a quotation for 3J21 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.
