COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF NITRONIC 50 (UNS S20910 / XM-19) FASTENING SYSTEMS
Nitronic 50, officially designated as UNS S20910 or Alloy XM-19, is a premium, nitrogen-strengthened austenitic stainless steel. It represents a massive metallurgical leap over standard 300-series alloys, providing a unique combination of corrosion resistance that supersedes Type 316L, alongside a yield strength that is roughly double that of conventional austenitic stainless steels.
Unlike martensitic or precipitation-hardening grades, Nitronic 50 achieves its immense strength without heat treatment, relying instead on nitrogen-alloying and cold working. Furthermore, it remains completely non-magnetic even after severe cold deformation. This makes XM-19 the ultimate fastener choice for demanding marine environments, urea production facilities, and subsea petrochemical infrastructure where high strength, extremely low magnetic permeability, and severe chloride resistance are simultaneously required.
■ Product Overview & Specifications
Nitronic 50 is typically supplied in two primary conditions for fastening applications: Annealed (for optimal corrosion resistance) and High-Strength / Cold-Worked (for maximum structural load capacity).
| Material Classification | Nitrogen-Strengthened Austenitic Stainless Steel |
|---|---|
| UNS Designation | S20910 (Alloy XM-19) |
| Microstructure | Fully Austenitic |
| Magnetic State | Consistently Non-Magnetic (Even after cold working) |
| Density | ~7.88 g/cm³ (0.285 lb/in³) |
| Size Range | Metric: M6 to M100 | Imperial: 1/4" to 4" Custom high-strength cold-forged studs available. |
| Thread Types | UNC, UNF, 8UN, Metric Coarse, Metric Fine (Rolled threads strictly recommended) |
| Strengthening Method | Solid Solution Strengthening (Nitrogen) & Strain Hardening (Cold Work) |
■ Proprietary Datasheet Download (GATED)
Access professional-grade technical data for Nitronic 50, including PREN (Pitting Resistance Equivalent Number) calculations, cryogenic impact toughness charts, and magnetic permeability test limits.
Nitronic 50 (S20910) — Complete Technical Datasheet
Contains detailed comparisons of Annealed vs. High-Strength conditions, specific ASTM A193 Grade B8R compliance metrics, and extreme-sub-zero (cryogenic) fastening data.
⬇ DOWNLOAD DATASHEET■ MTC Integration Section
Due to its specialized use in lethal chemical service and deepwater marine environments, strict chemistry and mechanical verification is standard protocol for Ananka Nitronic 50 shipments.
- EN 10204 Type 3.1: Mandatory reporting of Nitrogen (N), Columbium (Cb), and Vanadium (V) levels to guarantee proper alloying, alongside certified yield strengths confirming either Annealed or High-Strength conditions.
- EN 10204 Type 3.2: Third-party witness testing (e.g., ABS, DNV) heavily utilized for critical offshore platforms and naval applications.
■ Chemical Composition (UNS S20910)
The alloy derives its exceptional performance from elevated Chromium and Molybdenum for pitting resistance, balanced by Manganese and Nitrogen to stabilize the austenite and double the yield strength.
| Chromium (Cr) | Nickel (Ni) | Manganese (Mn) | Molybdenum (Mo) | Nitrogen (N) | Columbium (Cb) + V | Carbon (C) |
|---|---|---|---|---|---|---|
| 20.5 – 23.5 | 11.5 – 13.5 | 4.0 – 6.0 | 1.50 – 3.00 | 0.20 – 0.40 | 0.10 – 0.60 | 0.06 Max |
*Silicon is capped at 1.00 Max. The addition of Columbium (Niobium) and Vanadium provides high-temperature stabilization against intergranular corrosion.
■ Mechanical Properties (By Condition)
XM-19 is unique because its "Annealed" base state is already much stronger than standard 316. When ordered in the "High Strength" (cold worked) condition, it achieves strength levels comparable to low-alloy carbon steels.
| Property | Annealed Condition | High Strength (Cold Worked) |
|---|---|---|
| Tensile Strength (Min) | 100 ksi (690 MPa) | 135 ksi (930 MPa) |
| Yield Strength (0.2% Offset, Min) | 55 ksi (380 MPa) | 105 ksi (725 MPa) |
| Elongation in 2" (Min) | 35% | 15% |
| Reduction of Area (Min) | 55% | 45% |
| Hardness | ~95 HRB | 28 to 35 HRC |
■ Equivalent Grades & Designations
| Standard / System | Designation |
|---|---|
| UNS Designation | S20910 |
| ASTM Fastener Specs | ASTM A193 Grade B8R / ASTM A194 Grade 8R |
| Common Trade Name | Nitronic 50®, Alloy XM-19, Fermonic 50® |
| European Equivalent | EN 1.3964 / X2CrNiMnMoNNb21-16-5-3 |
■ Applications & Industries
Nitronic 50 is specified when the corrosion resistance of 316 is insufficient, or when structural designs require massive weight reduction through higher yield strengths.
- Marine & Naval: Non-magnetic deep-water fastening, boat shafting, and marine hardware exposed to stagnant seawater.
- Chemical & Fertilizer Processing: The global standard for urea production equipment, nitric acid processing, and severe sulfide environments.
- Cryogenic Storage: Liquid natural gas (LNG) and liquid oxygen structural bolting, as it retains high impact toughness at extreme sub-zero temperatures.
- Medical & MRI: High-strength structural components where absolute non-magnetic transparency is required.
■ Compatible Fastener Assemblies
To maximize performance and prevent thread seizure, thoughtful mating of Nitronic 50 components is necessary.
| External Threads (Nitronic 50 Studs/Bolts) | Recommended Mating Component (Nuts) |
|---|---|
| ASTM A193 Grade B8R (Nitronic 50) | ASTM A194 Grade 8R (Nitronic 50 Nuts) (Requires heavy lubrication) |
| ASTM A193 Grade B8R (Nitronic 50) | Nitronic 60 (UNS S21800) Nuts (Best practice for zero-galling and multiple re-uses) |
■ Torque & Installation Guidelines
Due to its high yield strength, Nitronic 50 (especially in the cold-worked condition) can handle higher torque loads than standard 300-series stainless. However, as a fully austenitic alloy, it remains highly susceptible to galling. High-pressure molybdenum-disulfide (MoS2) anti-seize must be used.
| Nominal Diameter | Threads Per Inch (UNC) | Target Torque (High Strength) — Lubricated (ft-lbs) |
|---|---|---|
| 1/2" | 13 | 55 - 65 |
| 5/8" | 11 | 110 - 130 |
| 3/4" | 10 | 190 - 220 |
| 1" | 8 | 450 - 520 |
■ Why Choose Ananka Group?
Ananka Group operates at the forefront of nitrogen-strengthened alloy manufacturing for critical infrastructure.
- Cold-Forging Expertise: We specialize in producing High-Strength condition Nitronic 50 fasteners through controlled strain hardening, maximizing yield without compromising corrosion resistance.
- Rolled Threads: Threads are rolled, not cut, whenever physically possible. This is critical for Nitronic 50 to maximize fatigue life and increase surface hardness to resist galling.
- Magnetic Permeability Testing: Full internal capabilities to certify absolute non-magnetic compliance for MRI, defense, and specialized radar applications.
- Certifications: Compliant with NACE MR0175 / ISO 15156 for sour gas environments and PED 2014/68/EU for European pressure equipment.
■ Frequently Asked Questions
1. How much stronger is Nitronic 50 than 316 Stainless Steel?
In its standard Annealed condition, Nitronic 50 has a minimum yield strength of 55 ksi, nearly double the 30 ksi yield of 316. In its High-Strength (cold worked) condition, the yield strength jumps to over 105 ksi, making it more than three times stronger than standard 316 stainless.
2. Will Nitronic 50 become magnetic if I hammer or bend it?
No. Standard 304 and 316 stainless steels often become slightly magnetic when cold-worked, machined, or impacted. Nitronic 50 is heavily alloyed with Nitrogen and Manganese, which heavily stabilize the austenite, meaning it remains completely non-magnetic under almost all extreme physical deformations.
3. Can it be used in high-temperature environments?
Yes, Nitronic 50 performs very well at elevated temperatures, maintaining excellent strength and oxidation resistance up to 1200°F (649°C). However, for applications requiring heavy load-bearing above 1000°F, alloys like A286 (Grade 660) might be a better design choice.
4. What does the "Nitronic" name mean?
Nitronic is a registered trademark of AK Steel Corporation. It refers to a family of austenitic stainless steels that utilize Nitrogen (N) as a primary strengthening agent instead of relying on high carbon or heat treatments. The generic equivalent for Nitronic 50 is UNS S20910 or XM-19.