Stainless Steel 1.4378
EN 1.4378
1.4378 (X6CrMnNiN18-13-3) is a nitrogen-strengthened austenitic stainless steel in which about 13 % manganese replaces most of the nickel, supplied solution annealed (+AT) or in the cold-worked classes +C700 to +C1000.
Reference datasheet — 1.4378 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +AT condition
1.4378 tempers and conditions
1.4378 is supplied in 5 conditions, soft to hard. +AT is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ATDefault Solution annealed | Standard stock condition: maximum ductility, non-magnetic, best corrosion resistance — pick for forming, deep drawing and welded fabrication. | 430 | 780 | 50 | 200 HB | — |
Cold worked to Rm ≥ 700 MPa | Lightly cold-drawn bar/wire: modest strength gain while keeping good ductility for cold heading and bending. | 480 | 760 | 25 | 225 HB | — |
Cold worked to Rm ≥ 800 MPa | Standard cold-drawn bar strength class for shafts, pins and property-class fasteners needing higher yield than annealed. | 600 | 860 | 18 | 24 HRC | — |
Cold worked to Rm ≥ 900 MPa | Higher-strength drawn bar/wire for loaded fasteners and spring-like parts where 304 cold-worked strength is not enough. | 720 | 960 | 14 | 28 HRC | — |
Cold worked to Rm ≥ 1000 MPa | Heavily drawn condition for maximum strength in small-section bar, wire and springs; ductility and cold-forming capacity are largely used up. | 830 | 1,060 | 11 | 32 HRC | — |
What is 1.4378?
1.4378 (X6CrMnNiN18-13-3) is a nitrogen-strengthened austenitic stainless steel in which about 13 % manganese replaces most of the nickel, supplied solution annealed (+AT) or in the cold-worked classes +C700 to +C1000. Annealed properties are 430 MPa yield, 780 MPa tensile, 50 % elongation and 200 HB, with a service ceiling near 800 °C, so it covers 304-level duty in structural and fastener work at lower nickel content. Corrosion resistance scores 60 — the best of the Cr-Mn grades but below 316 — while machinability is low at 33; 304/1.4301 is the nearest direct alternative. 1.4378 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,380°C (2,516 °F). 1.4378 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 50% and the elastic modulus is 197 GPa (28.6 Msi).
What is 1.4378 used for?
- structural components
- fasteners
- transportation equipment
- industrial fixtures
Advantages
- Ductile — tolerates forming and impact — 50%, better than 90% of stainless steel grades
- Low embodied carbon — 3.7 kg CO₂/kg, better than 78% of stainless steel grades
1.4378 properties
Typical room-temperature values for 1.4378-+AT; bars are the position among stainless steel grades.
Physical3
1.4378 has a density of 7.8 g/cm³ (0.282 lb/in³), heavier than 50% of stainless steel grades. It melts at 1,380°C (2,516 °F).
Mechanical15
1.4378 has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 67% of stainless steel grades. Elongation at break is 50% and the elastic modulus is 197 GPa (28.6 Msi).
Thermal6
1.4378 is rated for continuous service to 800°C (1,472 °F). It conducts heat at 14 W/m·K (8.09 BTU/hr·ft·°F), worse than 80% of stainless steel grades. Thermal expansion is 15.5 µm/m·K (8.61 µin/in·°F).
Electrical3
1.4378 conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4378 takes about 46 MJ of energy and emits 3.7 kg of CO₂ — less than 88% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
1.4378's machinability is poor (33/100, worse than 57% of stainless steel grades); weldability very good (75/100); formability good (65/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 1.4378 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4378
Is 1.4378 easy to machine?
Machines like a tough 304 but work-hardens faster — use rigid setups, sharp positive-rake carbide, heavy constant feed, low-to-moderate speed and flood coolant; avoid dwelling or rubbing.
Can 1.4378 be welded?
Readily welded by GTAW/GMAW/SMAW without preheat; use 307/308L-type or over-alloyed Cr-Ni-Mn filler, keep heat input and interpass temperature low, and no post-weld stress relief in the 550–800 °C sensitisation range.
Can 1.4378 be formed, bent or molded?
Excellent cold formability in +AT but very high work-hardening rate: expect 20–40 % higher press loads and more springback than 304, use interstage annealing for severe draws.
1.4378 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C≤0.08 % (X6 designation) | ≤ 0.08 | 0.06 |
| Si | ≤ 1 | 0.5 |
| Mnaustenite stabiliser replacing Ni | 11.5 – 14.5 | 13 |
| P | ≤ 0.05 | |
| S | ≤ 0.03 | |
| Cr | 17 – 19 | 18 |
| Ni | 2.5 – 4.5 | 3.2 |
| Nsolid-solution strengthening + austenite stability | 0.2 – 0.4 | 0.3 |
| Fe | balance |
What surface finishes work on 1.4378?
Not anodizable — passivate per ASTM A967, electropolish or mechanically polish; takes bright architectural and PVD finishes well, but a slightly higher sulphur/manganese level can leave more fine inclusion pitting on mirror polish.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Organic Coating
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 1.4378 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- X6CrMnNiN18-13-3
How much does 1.4378 cost?
1.4378 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
1.4378 — frequently asked
What is 1.4378 used for?
1.4378 is typically used for structural components, fasteners, transportation equipment and industrial fixtures. In short: nickel-lean 304 replacement; nitrogen-strengthened, 430 MPa yield; best corrosion of the 2xx set.
What is the yield strength of 1.4378?
1.4378 has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 780 MPa (113 ksi) — stronger than 67% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4378 easy to machine?
Not especially — machinability is rated poor (33/100, worse than 57% of stainless steel grades). Machines like a tough 304 but work-hardens faster — use rigid setups, sharp positive-rake carbide, heavy constant feed, low-to-moderate speed and flood coolant; avoid dwelling or rubbing.
Can 1.4378 be welded?
Yes — weldability is rated very good (75/100). Readily welded by GTAW/GMAW/SMAW without preheat; use 307/308L-type or over-alloyed Cr-Ni-Mn filler, keep heat input and interpass temperature low, and no post-weld stress relief in the 550–800 °C sensitisation range.
What surface finishes work on 1.4378?
Not anodizable — passivate per ASTM A967, electropolish or mechanically polish; takes bright architectural and PVD finishes well, but a slightly higher sulphur/manganese level can leave more fine inclusion pitting on mirror polish.
Can 1.4378 be formed, bent or molded?
Excellent cold formability in +AT but very high work-hardening rate: expect 20–40 % higher press loads and more springback than 304, use interstage annealing for severe draws.
What is the maximum service temperature of 1.4378?
1.4378 is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 1.4378 cost?
1.4378 is a premium-cost stainless steel ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10088-1/-2/-3 Stainless steels — grades, sheet/strip and bar — CEN (2014)
- ASTM A240 / A276 (UNS S24000, 18Cr-13Mn-3Ni-N) — ASTM International (2023)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- Nitrogen-strengthened Cr-Mn austenitic stainless (S24000/Nitronic 33-type) datasheet — Stainless producer (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.