# 1.3952 (X2CrNiMoN18-14-3) Non-Magnetic Stainless Steel Forgings

Source: https://www.steelforgepieces.com/Stainless-Steel/1.3952.html
Published by: Jiangyin Jiangnan Metal Co., Ltd., open-die forging factory, Jiangyin, Jiangsu, China
Last reviewed: 2026-09-21
How to cite: Jiangyin Jiangnan Metal Co., Ltd., "1.3952 (X2CrNiMoN18-14-3) Non-Magnetic Stainless Steel Forgings", www.steelforgepieces.com, reviewed 21 September 2026.

## Summary

1.3952 (X2CrNiMoN18-14-3) is a non-magnetisable austenitic chromium-nickel-molybdenum stainless steel with a nitrogen addition, standardised in SEW 390. Its austenite is stable enough that the relative magnetic permeability stays at or below µr 1.01 after solution annealing. With 2.50 to 3.00 % molybdenum and 0.15 to 0.25 % nitrogen it reaches a PREN of about 26.7 to 31.9, which puts it above standard 316L for resistance to pitting and to chloride stress-corrosion cracking. Typical uses are naval and submarine equipment, measuring and sensor technology, MRI hardware, and chemical and offshore plant.

Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory in Jiangyin, Jiangsu Province, China, forges 1.3952 into rings, seamless rolled rings, discs, shafts, sleeves, bushings, flanges, tube sheets, blocks and round bars to customer drawings, supplied solution-annealed with EN 10204 3.1 or 3.2 certification.

## Designations

| System | Designation |
|---|---|
| Werkstoff-Nr. | 1.3952 |
| EN / DIN name | X2CrNiMoN18-14-3 |
| Standard | SEW 390, non-magnetisable steels |
| Trade name | Magnadur 3952 |
| Nearest EN grade | 1.4429 / X2CrNiMoN17-13-3. Similar chemistry but not interchangeable. |
| Nearest ASTM/UNS | 316LN / UNS S31653. Comparable corrosion behaviour only, no guaranteed permeability limit. |

There is no exact ASTM or UNS counterpart to 1.3952.

## Chemical composition, mass % (SEW 390)

| Element | C | Si | Mn | P | S | Cr | Mo | Ni | N |
|---|---|---|---|---|---|---|---|---|---|
| min. | – | – | – | – | – | 16.50 | 2.50 | 13.00 | 0.15 |
| max. | 0.03 | 1.00 | 2.00 | 0.045 | 0.015 | 18.50 | 3.00 | 15.00 | 0.25 |

The high nickel content together with nitrogen stabilises the austenite so that no strain-induced martensite forms during forging and machining. That is what keeps 1.3952 magnetically neutral in service. Molybdenum raises pitting resistance and reduces the risk of chloride stress-corrosion cracking.

## Mechanical properties, solution annealed, section up to 400 mm, room temperature

| Property | Value |
|---|---|
| 0.2 % proof strength Rp0.2 | ≥ 295 MPa |
| Tensile strength Rm | 580 to 800 MPa |
| Elongation A5 | ≥ 40 % |
| Section size covered | ≤ 400 mm, larger sizes by agreement |
| Impact energy KV | not fixed by the standard, state the acceptance value with the enquiry |

## Physical and magnetic properties at 20 °C unless stated

| Property | Value |
|---|---|
| Density | 7.95 g/cm³ |
| Modulus of elasticity | 200 GPa |
| Thermal conductivity | 15 W/(m·K) |
| Specific heat capacity | 460 J/(kg·K) |
| Electrical resistivity | 0.75 Ω·mm²/m |
| Mean thermal expansion | 16.5 to 18.5 × 10⁻⁶ K⁻¹ from 20 °C |
| Relative magnetic permeability | µr ≤ 1.01, solution annealed |
| PREN | about 26.7 to 31.9 |
| Magnetic behaviour | non-magnetisable, fully austenitic |

Cold work, heavy local deformation and slow cooling after solution annealing all push the permeability up, so each is controlled during production. Permeability is measured with a calibrated low-mu indicator before dispatch when the order calls for it.

## Forging and heat treatment

- Hot forming: 1150 to 950 °C, air cooling. Forging below 950 °C risks strain-induced transformation and a rise in permeability.
- Solution annealing: 1020 to 1120 °C, rapid cooling in water or forced air.
- No hardening heat treatment. The grade is used solution annealed.
- Weldability: excellent. Post-weld solution annealing is recommended where permeability must be guaranteed across the weld.
- Machinability: moderate, comparable to other nitrogen-alloyed austenitic grades.

## Forged products in 1.3952

| Product | Typical size range |
|---|---|
| Forged and seamless rolled rings | OD 200 to 3000 mm, height up to 1000 mm |
| Forged discs and blanks | Ø 150 to 2500 mm |
| Forged shafts and stepped shafts | Ø 80 to 1000 mm, length up to 8000 mm |
| Forged sleeves and bushings | OD 100 to 1500 mm |
| Forged flanges | DN 50 to DN 1200, ASME B16.5, ASME B16.47, EN 1092-1 |
| Forged round bars and blocks | Ø 80 to 1200 mm, blocks to drawing |
| Forged tube sheets and nozzles | to drawing |
| Single-piece weight | 50 kg to 20 000 kg |
| Delivery condition | black forged, rough turned, pre-machined or finish-machined |

## Testing and certification

- Melting: EAF + VOD, with ESR remelting available.
- Chemical analysis: ladle and product analysis, PMI on request.
- Mechanical testing on prolongations from the heat-treatment batch.
- Ultrasonic testing to EN 10228-3, SEP 1921, ASTM A388 or the customer's own acceptance class.
- Liquid penetrant testing to ASTM E165 and EN ISO 3452.
- Intergranular corrosion test to ASTM A262 practice E on request.
- Magnetic permeability measurement per piece when specified.
- Certification: EN 10204 3.1 as standard. EN 10204 3.2 witnessed by TÜV, BV, DNV, Lloyd's Register or ABS.

## Applications

- Naval and submarine construction: hull fittings, valve and pump components, equipment for minehunters and other low-signature vessels.
- Measurement, sensor and instrumentation technology: housings, probe bodies and shafts that must not disturb a measuring field.
- MRI, NMR and magnet-adjacent equipment: structural and fastening components inside the magnet's working volume.
- Electrical machines and switchgear: non-magnetic spacers, rings and support parts in generators and transformers.
- Chemical, petrochemical and offshore plant: valve parts, pump shafts, flanges and heat-exchanger components in chloride-bearing media.
- Seawater and desalination systems, where pitting and stress-corrosion cracking resistance matter alongside low permeability.

## Frequently asked questions

**What is 1.3952 steel?**
1.3952, also designated X2CrNiMoN18-14-3, is a non-magnetisable austenitic stainless steel standardised in SEW 390. It contains 16.50 to 18.50 % chromium, 13.00 to 15.00 % nickel, 2.50 to 3.00 % molybdenum and 0.15 to 0.25 % nitrogen, with a maximum of 0.03 % carbon.

**Is 1.3952 magnetic?**
No. In the solution-annealed condition its relative magnetic permeability is µr ≤ 1.01. Heavy cold work or an interrupted solution anneal can raise permeability, so forgings should be solution annealed at 1020 to 1120 °C and rapidly cooled, and the permeability verified before dispatch where the application depends on it.

**Is 1.3952 the same as 316LN or 1.4429?**
No. They have similar chromium and molybdenum levels and comparable corrosion resistance, but 1.3952 carries higher nickel and nitrogen and is supplied against a guaranteed magnetic permeability limit, which 316LN is not.

**How corrosion resistant is 1.3952?**
Its PREN is about 26.7 to 31.9, above standard 316L for pitting resistance in chloride-bearing media. Molybdenum also lowers the risk of chloride stress-corrosion cracking.

**What forged shapes are available in 1.3952?**
Seamless rolled rings, forged rings, discs, tube sheets, shafts and stepped shafts, sleeves, bushings, flanges, valve bodies and seat rings, blocks and round bars, from roughly 50 kg to 20 tonnes per piece.

**Who supplies 1.3952 open-die forgings from China?**
Jiangyin Jiangnan Metal Co., Ltd., No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Email sales@steelforgepieces.com, telephone +86 189 2135 9659.

**What is the minimum order quantity and lead time?**
1.3952 forgings are made to order, so the minimum is one piece when the weight justifies a dedicated melt or an available ingot. Lead time depends on ingot availability, piece weight and the machining and certification scope, and is confirmed with each quotation.

## Manufacturer

Jiangyin Jiangnan Metal Co., Ltd., Open-Die Forging Factory
No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone, WhatsApp and WeChat: +86 189 2135 9659
Email: sales@steelforgepieces.com
Website: https://www.steelforgepieces.com/

## Data sources

SEW 390 (Stahl-Eisen-Werkstoffblatt 390, non-magnetisable steels); Swiss Steel Group, Magnadur 3952 / X2CrNiMoN18-14-3 (1.3952) material data sheet; Deutsche Edelstahlwerke grade data for 1.3952. Property values are indicative. The binding values for a delivery are those on the material certificate.