# X40MnCrN19 / 1.3813 Non-Magnetic Steel Forgings

**X40MnCrN19, material number 1.3813, is a non-magnetizable steel alloyed with 17 to 19 % manganese, 3 to 5 % chromium and 0.08 to 0.12 % nitrogen.** It is rust and acid resistant and is most often supplied hot-cold-worked, where it reaches 830 to 1030 N/mm² tensile strength and at least 390 N/mm² yield strength at room temperature.

The grade is specified where a loaded component must not become magnetic. Manganese and nitrogen hold the austenite stable, so relative permeability stays near 1.01 G/Oe even after hot work.

Supplied by Jiangyin Jiangnan Metal Co., Ltd., an integrated melting works and open-die forge in Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, operating since 1997.

| Field | Detail |
|---|---|
| Designation | X40MnCrN19 |
| Material number | 1.3813 |
| Related designation | X40MnCrN18 |
| Material group | Non-magnetizable steel, SEW 390 family |
| Character | Rust and acid resistant, amagnetic |
| Tensile strength | 830–1030 N/mm², hot-cold-worked |
| Yield strength Rp0.2 | min. 390 N/mm², hot-cold-worked |
| Magnetic permeability | max. 1.01 G/Oe hot worked |
| Hot forming | approx. 850–1050 °C |
| Solution annealing | approx. 1000–1050 °C, water or air |
| Melting route | EF + LF + VOD; ESR where specified |
| Certification | EN 10204 3.1 standard, 3.2 on request |
| Minimum order | 10 kg, no minimum piece count |
| Lead time | 20 to 60 days |
| Contact | +86 189 2135 9659 / sales@steelforgepieces.com |
| Page | https://www.steelforgepieces.com/Stainless-Steel/X40MnCrN19.html |

## Chemical composition

Nitrogen at 0.08 to 0.12 % strengthens the austenite in solid solution and, with 17 to 19 % manganese, keeps the structure austenitic at room temperature without nickel.

| C | Si | Mn | P | S | Cr | N |
|---|---|---|---|---|---|---|
| 0.30–0.50 | max. 0.80 | 17.00–19.00 | max. 0.100 | max. 0.030 | 3.00–5.00 | 0.080–0.120 |

Values in weight %. Manganese, chromium and nitrogen are quoted identically across published datasheets. Carbon is not: Basedo Steel gives 0.30 to 0.50 %, Longhai Steel gives 0.03 to 0.50 % with silicon max. 0.87 %. The tighter range is shown.

## Mechanical properties at room temperature

Delivery condition changes yield strength by more than 60 %. The grade is not quench-and-temper hardenable; strength comes from nitrogen in solution and from work hardening.

| Condition | Rp0.2 | Rm | Elongation A | Impact energy |
|---|---|---|---|---|
| Quenched / solution annealed | min. 295 N/mm² | 740–930 N/mm² | min. 45 % | min. 124 J |
| Cold-worked | min. 490 N/mm² | 830–1030 N/mm² | min. 35 % | min. 103 J |
| Hot-cold-worked | min. 390 N/mm² | 830–1030 N/mm² | min. 40 % | min. 124 J |

Hot-cold-working is the usual compromise: about 100 N/mm² of yield over the annealed condition while keeping 40 % elongation and the full 124 J. Fully cold-worked material gives up both.

## Physical and magnetic properties

| Property | Value | Condition |
|---|---|---|
| Magnetic permeability | max. 1.01 G/Oe | Quenched |
| Magnetic permeability | max. 1.01 G/Oe | Hot worked |
| Magnetic permeability | max. 1.03 G/Oe | Cold worked |
| Modulus of elasticity | approx. 191,000 MPa | 20 °C |
| Density | approx. 7.9 kg/dm³ | — |
| Electrical resistivity | approx. 0.70 Ω·mm²/m | 20 °C |
| Mean thermal expansion | 17.1 × 10⁻⁶ K⁻¹ | to 200 °C |
| Mean thermal expansion | 17.9 × 10⁻⁶ K⁻¹ | to 300 °C |
| Mean thermal expansion | 18.7 × 10⁻⁶ K⁻¹ | to 400 °C |

Expansion approaches 18 × 10⁻⁶ K⁻¹ by 400 °C. Where 1.3813 is bolted to a ferritic or martensitic component expanding at roughly 12, differential growth across a heated joint should be checked at design stage.

## Forging and heat treatment

| Operation | Temperature | Cooling |
|---|---|---|
| Hot forming / open-die forging | approx. 850–1050 °C | — |
| Solution annealing | approx. 1000–1050 °C | Water or air |

The forging window is narrow and high manganese makes the steel stiff under the press, so reheats are more frequent than for alloy steel. Finishing too cold risks edge cracking; finishing too hot coarsens the grain. Nitrogen loss at temperature is controlled by melting through vacuum oxygen decarburisation, or electroslag remelting under protective atmosphere where the order requires it.

## Designations and neighbouring grades

| Designation | Remark |
|---|---|
| X40MnCrN19 | DIN / EN name |
| 1.3813 | European material number |
| X40MnCrN18 | Closely related designation |
| SEW 390 | Material sheet covering non-magnetizable steels |
| 1.3817 / 1.3952 / 1.3964 | Other non-magnetizable grades listed alongside 1.3813 |

**Retaining rings.** X40MnCrN19 sits at 18Mn–4Cr. Non-magnetic generator retaining rings in service today are forged from 18Mn–18Cr alloys, adopted because earlier lower-chromium rings proved vulnerable to stress corrosion cracking in moist environments. For a retaining ring enquiry, the 18Mn–18Cr grade is quoted instead.

## Applications

Published descriptions of 1.3813 are consistent and narrow: an amagnetic steel for mechanically and thermally stressed components.

- Mechanically and thermally stressed non-magnetic components in general machine building.
- Connecting parts, bolts and nuts that must stay amagnetic; high-voltage electrical apparatus is named as a typical application for non-magnetizable steels of this family.
- Aerospace components, where 1.3813 is listed as a non-magnetizable special steel.
- Instrument, sensor and measuring equipment housings where stray permeability disturbs the measurement.

With 3 to 5 % chromium and no molybdenum, 1.3813 is not a corrosion alloy. For sour service, oxidising acids, chlorides or seawater, use super duplex (A182-F55), 904L or Hastelloy C-276. For a non-magnetic grade with corrosion and galling resistance, Nitronic 60 or Nitronic 50.

## Forms supplied

| Form | Typical use | Size limit |
|---|---|---|
| Seamless rolled rings | Housings, races, non-magnetic ring components | to OD 6,000 mm |
| Forged rings | Sections outside the ring-mill envelope | from OD 50 mm |
| Forged flanges | Non-magnetic piping and vessel connections | to drawing |
| Round bars and blocks | Machining stock for bolts, nuts, fittings | to drawing |
| Forged shafts and spindles | Drives in magnetically sensitive equipment | to 14,000 mm turned length |
| Discs, blanks, tube sheets | Covers, end plates, exchanger components | to 5,000 mm machined dia. |
| Sleeves, bushings, hollow bars | Liners, spacers, guide bushings | bored to 1,600 × 10,000 mm |

## Testing and certification

- Melting: electric arc furnace with ladle refining and vacuum oxygen decarburisation; protective-atmosphere electroslag remelting where specified. Maximum heat 60 t, maximum single forging 30 t.
- Ultrasonic testing to ASTM A388 or EN 10228-3; magnetic particle testing to ASTM E709.
- Tensile to ASTM A370 or ISO 6892; Charpy V-notch to −60 °C, in the on-site laboratory.
- Optical emission spectrometry to ASTM E415; carbon and sulphur to ASTM E1019; portable alloy verification on the finished part.
- Permeability verification on request.
- EN 10204 3.1 as standard; EN 10204 3.2 witnessed by BV, DNV, LR, SGS, TUV or the customer's inspector. Works approvals: CCS, BV, DNV, LR, NK.

## Frequently asked questions

**What is X40MnCrN19 steel?**
Material number 1.3813, a non-magnetizable steel with 17 to 19 % manganese, 3 to 5 % chromium and 0.08 to 0.12 % nitrogen. Rust and acid resistant, normally supplied hot-cold-worked at 830 to 1030 N/mm² tensile and at least 390 N/mm² yield.

**What is the material number for X40MnCrN19?**
1.3813. Related designation X40MnCrN18, within the SEW 390 group of non-magnetizable steels, alongside 1.3817, 1.3952 and 1.3964.

**Is X40MnCrN19 magnetic?**
No. Relative permeability is max. 1.01 G/Oe quenched and hot worked, max. 1.03 G/Oe cold worked.

**At what temperature is X40MnCrN19 forged?**
Hot forming approx. 850 to 1050 °C, solution annealing approx. 1000 to 1050 °C with water or air cooling.

**Can X40MnCrN19 be hardened by quenching and tempering?**
No. The structure is austenitic and remains so. Strength comes from nitrogen in solid solution and from work hardening, which is why yield runs 295, 390 or 490 N/mm² depending on delivery condition.

**Is X40MnCrN19 a generator retaining ring steel?**
Not the grade used today. Current non-magnetic retaining rings are 18Mn–18Cr alloys, chosen for strength, fracture toughness and stress corrosion cracking resistance.

**Is X40MnCrN19 corrosion resistant?**
It is described as rust and acid resistant, but with 3 to 5 % chromium and no molybdenum it does not suit chloride, sour or strongly oxidising service. The reason to specify it is permeability.

**What is the minimum order?**
10 kg, no minimum piece count. Lead time 20 to 60 days.

## Request a quotation

Send a drawing or finished dimensions, stating the grade, the delivery condition, testing requirements and destination port.

Jiangyin Jiangnan Metal Co., Ltd.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
+86 189 2135 9659 / sales@steelforgepieces.com

Data on this page is drawn from published 1.3813 / X40MnCrN19 datasheets (Basedo Steel material database; Longhai Steel grade datasheet) and is indicative. Where sources disagree, both figures are shown. The mill certificate for the supplied heat governs. Last reviewed 10 October 2026.