Welcome to RAYCHIN LIMITED

+86-531-59532816



Alloy 20 Fasteners



Location： HOME - Special Fasteners - Alloy 20 Fasteners - Alloy 20 Threaded Rods

Alloy 20 Threaded Rods

Alloy 20 Threaded Rods, also known as Carpenter 20 and 20CB-3, offers a combination of nickel, chromium, molybdenum, and copper which provides good general corrosion resistance. Alloy 20 (2.4660) Threaded Rods are best suited for mid-range corrosion use – better than steel alloys but not at the level of high performance nickel based alloys like Hastelloy C276. Alloy 20 is a nickel alloy that was specifically designed to withstand the harsh environment of hot sulfuric acid but also performs well in a variety of other acids. Alloy 20 Threaded Rods are an ideal choice when you don’t need the corrosion resistance power and price-tag of high performance nickel alloys like Hastelloy C276; but you need something that will give you more protection than 316 stainless steel or even a Super Duplex 2507 stainless steel.

RAYCHIN SPECIALTY METALS FASTENERS: BOLTS, NUTS, SCREWS, WASHERS, STUDS, THREADED RODS, U-BOLT, J-BOLTS

STANDARD AND CUSTOMIZED, SMALL BATCH AND LARGE BATCH, IMPERIAL AND METRIC

Mid-range corrosion resistant alloy
Decent mechanical strength to 1000°F
Good sulfuric acid protection at 20% - 40%
Decent stress corrosion cracking, pitting and crevice corrosion resistance in chloride
Resonable general corrosion protection
Good intergranular corrosion resistance in the as-welded condition

Request a Quote from RAYCHIN

We're here to help!

Request a Quote

RAYCHIN LIMITED

Name: Alloy 20 Threaded Rods
SKU: 0

Specialist in Alloy 20 Threaded Rods · Fully Threaded · Continuous Thread · Custom

Alloy 20 Threaded Rods: Corrosion-Resistant Studding for Critical Applications

UNS N08020 / W. Nr. 2.4660 / 20Cb-3 / Carpenter 20 / Incoloy 20

RAYCHIN LIMITED is a recognized expert in Alloy 20 threaded rods — from Alloy 20 fully threaded rods, Alloy 20 continuous thread studs, Alloy 20 studding to custom non-standard configurations. Alloy 20 (UNS N08020) is a nickel-iron-chromium superalloy with additions of copper and molybdenum, stabilized with niobium. Also designated as 20Cb-3, Carpenter 20, and Incoloy 20, it maintains exceptional corrosion resistance in aggressive chemical environments up to 538°C (1000°F). This makes it the preferred material for threaded rods in sulfuric acid service, phosphoric acid handling, heat exchangers, chemical processing, oil & gas (sour service), pharmaceuticals, and food processing equipment requiring corrosion-resistant studding. Threaded rods, also known as fully threaded rods, continuous thread studs, or all-thread rods, feature continuous threads along their entire length, allowing them to be cut to any length and used with standard nuts and washers. They are essential components in pipe supports, flange connections, tension applications, and structural assemblies. The alloy's high nickel content (32-38%) provides immunity to chloride stress corrosion cracking, while copper and molybdenum additions enhance resistance to reducing acids. Our portfolio includes threaded rods manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS standards. Engineered for extreme environments where corrosion resistance and versatility are critical. Alloy 20 threaded rods are supplied in solution annealed condition with full traceability and third-party certifications.

Alloy 20 Threaded RodsAlloy 20 Fully Threaded RodsAlloy 20 Continuous Thread StudsAlloy 20 StuddingAlloy 20 All-Thread RodsUNS N08020 Threaded Rods2.4660 Threaded Rods20Cb-3 Threaded RodsCarpenter 20 Threaded RodsIncoloy 20 Threaded RodsASTM B473 Threaded RodsNACE MR0175 Threaded RodsDIN 975 Alloy 20 RodsDIN 976 Alloy 20 RodsASME B18.31.1M Alloy 20 Rodssulfuric acid resistant threaded rodscorrosion resistant studdingchemical processing threaded rodssour service threaded rodsheat exchanger threaded rods

Complete Range of Alloy 20 Threaded Rods – Configurations

Fully Threaded Rods (DIN 975 / ASME B18.31.1M)

Alloy 20 fully threaded rods manufactured to DIN 975, ISO 4014, and ASME B18.31.1M standards. Features continuous threads along the entire length for maximum versatility in applications requiring engagement along the full rod length. Ideal for high-temperature corrosive applications up to 538°C where custom lengths are required. Precision rolled threads for superior strength and corrosion resistance. Available in diameters from M6 to M100 (metric) and 1/4" to 4" (inch) in standard lengths of 1m, 2m, 3m, and custom lengths up to 6m. Supplied in solution annealed condition per ASTM B473. Suitable for pipe supports, flange connections, and tension applications.

Continuous Thread Studs (DIN 976 / ISO 4014)

Alloy 20 continuous thread studs manufactured to DIN 976, ISO 4014, and ASME B18.31.2 standards. Features continuous threads along the entire length, typically supplied in precision-cut lengths for specific applications. Ideal for heat exchangers, valve assemblies, and structural connections requiring high-temperature capability and corrosion resistance. Precision rolled UNC, UNF, and metric threads for superior fatigue resistance. Available in diameters from M6 to M100 (metric) and 1/4" to 4" (inch) in custom lengths. Supplied with passivated finish per ASTM A967. NACE MR0175 compliant for sour service applications.

Custom & Specialty Threaded Rods

Alloy 20 custom threaded rods manufactured to customer specifications. Need a special thread configuration, unusual length, or custom end preparation for your corrosive application? RAYCHIN engineers work with you to produce custom Alloy 20 threaded rods to your drawing. Options include extra-long lengths up to 6m, special thread classes, and custom end chamfers. Expert heat treatment (solution annealed at 1030-1120°C) ensures optimum corrosion resistance. Manufactured to NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN, KS standards.

Threaded Rod Design & Standards

Dimensional Standards

Our Alloy 20 threaded rods meet or exceed the following specifications:

Metric Fully Threaded	DIN 975, ISO 4014 (applicable)
Metric Continuous Thread	DIN 976, ISO 4014 (applicable)
Inch Fully Threaded	ASME B18.31.1M
Inch Continuous Thread	ASME B18.31.2
Thread Standards	UNC, UNF, UNJF-3A, Metric coarse/fine

Standard lengths: 1m, 2m, 3m (metric), 3ft, 6ft, 10ft (inch). Custom lengths available up to 6m.

Thread Classes & Finishes

Thread Classes: 2A, 3A, UNJF-3A, 6g, 6H
Passivated: Per ASTM A967 for maximum corrosion resistance
Electropolished: For clean room and pharmaceutical applications
PTFE Coated: For anti-galling and lubricity

Typical Applications

Heat exchanger tie rods
Pipe supports and hangers
Flange connections
Tension applications
Structural assemblies
Anchor bolts
U-bolt manufacturing

Key Benefits of Alloy 20 Threaded Rods

Exceptional Sulfuric Acid Resistance

Alloy 20 was specifically developed for sulfuric acid service and has become the industry standard for fasteners in aggressive chemical environments. Offers good resistance to stress-corrosion cracking in boiling sulfuric acid at 20-40% concentration, as well as general sulfuric acid resistance. Corrosion rates typically below 0.5 mm/year across most concentrations.

Continuous Thread Design

Fully threaded along the entire length, allowing cutting to any required length for custom applications. Provides maximum versatility for field modifications and custom installations.

Chloride SCC Immunity

With 32-38% nickel content, Alloy 20 offers practical immunity to chloride stress corrosion cracking, making it ideal for marine and brackish water applications where 304/316 threaded rods would fail.

Sour Service Approved

NACE MR0175 / ISO 15156 qualified for H₂S environments. Suitable for wellhead equipment, valve assemblies, and subsea connections in oil and gas applications requiring corrosion-resistant threaded rods.

Long Length Capability

Available in lengths up to 6 meters (20 feet), allowing for continuous runs without joints or couplings. Ideal for long-span applications and custom installations.

Temperature Versatility

Maintains useful mechanical properties up to 538°C (1000°F), suitable for heat exchanger and process equipment applications at elevated temperatures.

Manufacturing Standards for Alloy 20 Threaded Rods

RAYCHIN LIMITED manufactures Alloy 20 threaded rods to the following national and international standards, ensuring full compliance for projects worldwide. Both standard and non-standard custom configurations are available.

NASANMSANSIASTMASMESAEAPINACEISODINKSJISGB

International Standards & Global Designations for Alloy 20 Threaded Rods

To serve clients worldwide, RAYCHIN LIMITED manufactures Alloy 20 threaded rods from material conforming to the following national and international specifications. This ensures full compliance for projects in the Americas, Europe, Asia, and the Middle East.

Country / Region	Standard / Specification	Designation / Grade
USA	ASTM B473 / ASME SB473, ASTM B462, ASTM B463, ASTM F2281, UNS N08020	Alloy 20 · 20Cb-3 · Carpenter 20 · Incoloy 20
Germany (DIN)	W. Nr. 2.4660, DIN 17744, DIN 975 (fully threaded rods), DIN 976 (continuous thread studs)	2.4660 · NiCr20CuMo
Europe (CEN)	EN 10269 (for fasteners), EN 10095	1.4500 (similar designation)
France (NF)	NF A35-572/573	Z2NCDU25-20
UK (BS)	BS 3076, BS 4882 (threaded rods)	NA 20
China (GB)	GB/T 15007, GB/T 1220, GB/T 3098.6	NS1403 · 0Cr20Ni35Mo3Cu4Nb
Japan (JIS)	JIS G4903, JIS G4904	NCF 20
ISO	ISO 15156-3 (NACE MR0175), ISO 4014 (applicable)	UNS N08020
NACE	NACE MR0175 / ISO 15156	Alloy 20 (qualified for sour service)
API	API 20F	Alloy 20

UNS N08020 2.4660 ASTM B473 ASME SB473 NACE MR0175 20Cb-3 Carpenter 20 Incoloy 20 DIN 975 DIN 976 ASME B18.31.1M ASME B18.31.2

Chemical Composition (Weight %) – Alloy 20 (UNS N08020 / 2.4660)

Our Alloy 20 threaded rods are produced from melts that strictly conform to the limits below per ASTM B473 / ASME SB473. The high nickel content provides immunity to chloride stress corrosion cracking, while chromium ensures resistance to oxidizing media. Copper and molybdenum provide exceptional resistance to reducing acids such as sulfuric and phosphoric acids. Niobium stabilization prevents intergranular corrosion.

Element	ASTM B473 / ASME SB473 (Range %)	Typical (analysis)
Nickel (Ni)	32.0 – 38.0	34.0
Chromium (Cr)	19.0 – 21.0	20.0
Copper (Cu)	3.0 – 4.0	3.5
Molybdenum (Mo)	2.0 – 3.0	2.5
Niobium + Tantalum (Nb+Ta)	8 x C min – 1.0 max	0.5
Carbon (C)	≤ 0.07	0.03
Manganese (Mn)	≤ 2.00	1.2
Phosphorus (P)	≤ 0.045	0.020
Sulfur (S)	≤ 0.035	0.010
Silicon (Si)	≤ 1.00	0.5
Iron (Fe)	Balance	Balance

Expert note: The nickel content (32-38%) places Alloy 20 in the austenitic superalloy category, providing exceptional resistance to chloride stress corrosion cracking. Copper (3-4%) is the key element for sulfuric acid resistance, while molybdenum (2-3%) enhances pitting resistance. Niobium stabilization prevents chromium carbide precipitation at grain boundaries, maintaining corrosion resistance after welding or thermal processing.

Complete Mechanical Properties of Alloy 20 Threaded Rods (per ASTM B473)

Alloy 20 threaded rods are supplied in the solution annealed condition (1030-1120°C followed by rapid quenching). The data below represent minimum requirements per ASTM B473 / ASME SB473 unless otherwise noted.

Tensile Requirements – ASTM B473 (Bar & Fastener Stock)

Size Range	Tensile Strength (min)	Yield Strength 0.2% Offset (min)	Elongation (min)	Reduction of Area (min)
All sizes	550 MPa (80 ksi)	240 MPa (35 ksi)	30%	50%

Typical Mechanical Properties (Solution Annealed)

Property	Typical Value	Notes
Ultimate Tensile Strength	620 MPa (90 ksi)	Exceeds minimum requirements
Yield Strength (0.2% Offset)	300 MPa (43.5 ksi)	Exceeds minimum requirements
Elongation	40%	Excellent ductility
Hardness (Brinell)	217 HB max	Typically 150-190 HB
Hardness (Rockwell C)	19 HRC max	Typically 10-15 HRC
Modulus of Elasticity	193 GPa (28,000 ksi)	At room temperature
Poisson's Ratio	0.31	—
Electrical Resistivity (RT)	651 ohm-cir mil/ft	—

For NACE MR0175 / API 20F sour service applications, maximum hardness of 35 HRC is easily met (Alloy 20 typically below 20 HRC in annealed condition).

Elevated Temperature Mechanical Properties

Alloy 20 maintains useful mechanical properties at elevated temperatures up to approximately 538°C (1000°F), suitable for heat exchanger and process equipment applications.

Temperature	Yield Strength (typical)	Tensile Strength (typical)	Retention (%)
Room Temperature (20°C)	300 MPa	620 MPa	100%
100°C (212°F)	275 MPa	590 MPa	90-95%
200°C (392°F)	260 MPa	570 MPa	85-90%
300°C (572°F)	250 MPa	550 MPa	80-85%
400°C (752°F)	240 MPa	530 MPa	75-80%
500°C (932°F)	230 MPa	500 MPa	70-75%
538°C (1000°F)	220 MPa	480 MPa	65-70%

Note: For service above 538°C, nickel-based alloys such as Inconel 625 or 718 are recommended.

Physical Properties

Property	Value
Density	8.08 g/cm³ (0.292 lb/in³)
Melting Point	1357 – 1430°C (2475 – 2606°F)
Thermal Expansion Coefficient (20-100°C)	14.7 x 10⁻⁶ /°C (8.2 µin/in-°F)
Thermal Conductivity (20°C)	12.3 W/m·K (85 Btu-in/ft²-hr-°F)
Specific Heat Capacity	0.45 J/g·°C
Electrical Resistivity (RT)	135.9 × 10⁻⁶ ohm-cm (53.5 µohm-in)
Magnetic Permeability	≤ 1.02 (non-magnetic)

Exceptional Corrosion Resistance of Alloy 20 Threaded Rods

Alloy 20 was originally developed for sulfuric acid service and has become the industry standard for fasteners in aggressive chemical environments. The combination of nickel, chromium, copper, and molybdenum provides outstanding resistance to both oxidizing and reducing acids.

Sulfuric Acid Resistance

Alloy 20 threaded rods offer exceptional resistance to sulfuric acid across a wide range of concentrations and temperatures. The copper addition (3-4%) is particularly beneficial for sulfuric acid environments. Alloy 20 offers good resistance to stress-corrosion cracking in boiling sulfuric acid at 20-40% concentration, as well as general sulfuric acid resistance.

Concentration	Temperature	Corrosion Rate
Up to 50% H₂SO₄	Up to 80°C	< 0.5 mm/year (excellent)
50-80% H₂SO₄	Up to 50°C	< 0.5 mm/year (good)
80-95% H₂SO₄	Room temperature	< 0.5 mm/year (excellent)
All concentrations	Up to 50°C	< 0.5 mm/year (good)

Phosphoric & Nitric Acid Resistance

Excellent resistance to phosphoric acid, including wet process phosphoric acid containing fluoride impurities. Also shows useful resistance to nitric acid. Widely used in fertilizer industry applications where threaded rods secure agitator blades, piping, and mixing equipment.

Chloride Stress Corrosion Cracking (SCC) Resistance

With 32-38% nickel content, Alloy 20 threaded rods have practical immunity to chloride stress corrosion cracking. This makes them ideal for marine environments, brackish water, and applications where chloride SCC is a concern with 300-series stainless steels.

Pitting and Crevice Corrosion Resistance

The molybdenum addition (2-3%) provides enhanced resistance to pitting and crevice corrosion in chloride-containing media. The Pitting Resistance Equivalent (PRE) is approximately 26-28, providing moderate resistance to localized corrosion in seawater and brine solutions.

Intergranular Corrosion Resistance

Alloy 20 is stabilized with columbium (niobium) to minimize carbide precipitation during welding. This provides excellent intergranular corrosion resistance in the as-welded condition, maintaining corrosion resistance at grain boundaries.

Resistance to Other Media

Environment	Resistance Level	Notes
Nitric Acid	Good	Chromium provides resistance to oxidizing acids
Hydrochloric Acid	Moderate	Limited resistance at higher concentrations/temperatures
Hydrofluoric Acid	Good	Resistant to all concentrations at room temperature, up to 10% HF at 70°C
Mixed Acids (H₂SO₄ + HNO₃)	Excellent	Widely used in nitration processes
Caustic Solutions	Good	Resistant to caustic soda and potash
Seawater	Good	Moderate resistance to pitting and crevice corrosion
Sour Service (H₂S)	Excellent	Qualified per NACE MR0175/ISO 15156

Special focus: Alloy 20 Threaded Rods for Critical Applications

For critical applications requiring exceptional corrosion resistance and versatile studding, RAYCHIN offers Alloy 20 threaded rods manufactured to ASTM, ASME, NACE, and customer-specific specifications. Our capabilities include:

Heat Exchangers: Tie rods, baffle rods, tube bundle assembly, floating head support rods.
Chemical Processing: Pipe supports, vessel internals, reactor connections, column internals, agitator support rods.
Sulfuric Acid Plants: Acid cooler supports, piping hangers, tower internals, pump supports, structural bracing.
Phosphoric Acid Production: Evaporator supports, reactor internals, pipe hangers, agitator rods.
Oil & Gas / Sour Service: NACE MR0175 compliant threaded rods for wellhead equipment, valve assembly tie rods, subsea structural supports.
Power Generation: Flue-gas desulfurization (FGD) systems, scrubber internals, boiler supports, duct hangers.
Pharmaceutical Manufacturing: Clean room supports, equipment framing, sanitary piping supports, vessel internals.
Food Processing: Mixer supports, tank framing, conveyor components, equipment stands.
Marine Applications: Pipe hangers, structural supports, equipment framing in seawater environments.
Water Treatment: Tank internals, filter supports, pipe hangers, structural bracing.
Standards: DIN 975, DIN 976 (metric), ASME B18.31.1M, ASME B18.31.2 (inch).
Thread Classes: 2A, 3A, UNJF-3A, 6g, 6H.
Sizes: M6 through M100, 1/4" through 4".
Lengths: Standard 1m, 2m, 3m (metric), 3ft, 6ft, 10ft (inch). Custom lengths up to 6m (20ft).
Certifications: EN 10204 3.1/3.2 material certifications, NACE MR0175, API 20F, PED 2014/68/EU.

All Alloy 20 threaded rods are supplied with full traceability and third-party NDT upon request. Material certifications included. Custom cutting and packaging available.

Why RAYCHIN LIMITED – The Alloy 20 Threaded Rod Authority

Metallurgical competence

Engineers on staff with deep expertise in nickel-based superalloys. We ensure proper solution annealing (1030-1120°C) for optimal corrosion resistance across all Alloy 20 threaded rods. Every heat is verified by in-house PMI testing to confirm chemistry. With 32-38% nickel and copper-molybdenum additions, our threaded rods provide exceptional resistance to sulfuric acid, phosphoric acid, and chloride stress corrosion cracking while maintaining excellent mechanical properties.

Global approvals & traceability

Our quality system is ISO 9001:2015 and AS9100D certified; we also comply with NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN and KS. Full material traceability from melt to final packaging (EN 10204 3.1/3.2). Third-party inspections (ABS, DNV, Lloyds) available. All Alloy 20 threaded rods meet applicable ASTM B473, ASME SB473, NACE MR0175, and rod standards including DIN 975, DIN 976, ASME B18.31.1M.

Precision thread rolling & long length capability

In-house CNC thread rolling and cutting capabilities ensure precise thread geometry and consistent mechanical properties. Capable of producing lengths up to 6 meters with consistent thread quality. Precision rolled threads provide superior fatigue life and dimensional accuracy. Available thread classes up to 3A/6g. 100% thread inspection available.

Custom solutions

Need a special thread configuration, unusual length, or custom end preparation for your corrosive application? Our engineering team works with you to produce custom Alloy 20 threaded rods to your drawing. We provide specialized surface treatments, passivation, and NACE MR0175 compliant processing per customer requirements.

Contact the Alloy 20 threaded rod experts today

Request a quote for Alloy 20 threaded rods, fully threaded rods, continuous thread studs & custom configurations – any global standard (NAS, AN, MS, ANSI, ASTM, ASME, SAE, API, NACE, ISO, DIN, KS), any quantity. Inquire about sulfuric acid resistant threaded rods, NACE MR0175 sour service requirements, or high-temperature applications.

sales@ray-chin.com | +86 534 2166 566

Our team speaks English, German, Mandarin, and Japanese – ready for your global procurement.

Request A Quote! We'll respond as soon as possible(within 12 hours)