Stainless Steel 1.4421
EN 1.4421
1.4421 (GX4CrNi16-4) is a molybdenum-free 16Cr-4Ni soft martensitic cast stainless steel, supplied quenched and tempered in the +QT1 and +QT2 conditions.
Reference datasheet — 1.4421 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 +QT1 condition
1.4421 tempers and conditions
1.4421 is supplied in 2 conditions, soft to hard. +QT1 is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+QT1Default Austenitized, air/oil quenched and high-temperature tempered | Standard supply condition for hydro turbine, pump and valve castings where toughness, weld repairability and impact energy matter more than peak strength. | 620 | 850 | 18 | 26 HRC | 25 W/m·K |
Austenitized, quenched and tempered at lower temperature | Choose when higher proof strength is required for highly loaded runners, impellers or hydraulic bodies and the lower impact energy / reduced sour-service margin is acceptable. | 880 | 1,050 | 13 | 34 HRC | 25 W/m·K |
What is 1.4421?
1.4421 (GX4CrNi16-4) is a molybdenum-free 16Cr-4Ni soft martensitic cast stainless steel, supplied quenched and tempered in the +QT1 and +QT2 conditions. Engineers select it where a casting must combine 620 MPa yield and 850 MPa tensile strength with 18 % elongation, 265 HB (26 HRC) and better corrosion resistance than 13Cr-4Ni grades, typically as sand or investment castings for hydraulic and pump duty. Elastic modulus is 200 GPa, thermal conductivity 25 W/m·K and maximum service temperature 400 °C. Machinability is limited (score 42) and the alloy has no molybdenum, so for chloride or seawater exposure a Mo-bearing soft martensitic or duplex casting is the closer fit; 1.6982/CA6NM is the nearest alternative. 1.4421 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F). 1.4421 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
What is 1.4421 used for?
- Hydraulic turbine components
- Pump casings and impellers
- General corrosion-resistant castings
Advantages
- Conducts heat well — 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades
- High strength — 620 MPa (89.9 ksi), better than 88% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
Limitations
- Limited formability — 10/100, worse than 95% of stainless steel grades
- Limited ductility — 18%, worse than 83% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
1.4421 properties
Typical room-temperature values for 1.4421-+QT1; bars are the position among stainless steel grades.
Physical3
1.4421 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4421 has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 88% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4421 is rated for continuous service to 400°C (752 °F). It conducts heat at 25 W/m·K (14.4 BTU/hr·ft·°F), better than 93% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4421 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (57/100), worse than 66% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4421 takes about 50 MJ of energy and emits 4.5 kg of CO₂ — less than 80% of stainless steel grades. Typical recycled content is 70%.
Manufacturability7
1.4421's machinability is fair (42/100, better than 79% of stainless steel grades); weldability very good (72/100); formability not recommended (10/100).
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. 1.4421 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4421
Is 1.4421 easy to machine?
Machine after tempering with rigid setups, sharp carbide tooling, moderate speed and heavy positive feed to avoid work hardening; the tough martensite makes chips stringy and drives insert notch wear.
Can 1.4421 be welded?
Very good for a martensitic grade: use matching 16-5 or 13-4 low-carbon consumables, preheat/interpass 100–160 °C, avoid excessive heat input, then post-weld temper below the original tempering temperature.
Can 1.4421 be formed, bent or molded?
Supplied as a casting — no cold forming; ensure directional solidification with adequate risering and hot isostatic pressing or weld repair for critical pressure/cavitation surfaces.
1.4421 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 |
|---|---|---|
| Clow carbon for soft martensite and weldability | ≤ 0.06 | 0.04 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 1 | 0.7 |
| P | ≤ 0.04 | |
| S | ≤ 0.03 | |
| Cr | 15 – 17 | 16 |
| Ni | 3.5 – 5 | 4.3 |
| Moresidual only — grade is nominally Mo-free | ≤ 0.7 | 0.2 |
| N | ≤ 0.05 | 0.03 |
| Fe | balance |
What surface finishes work on 1.4421?
Passivate after machining and grinding to restore the chromium oxide film; takes a fine ground/polished finish, and can be hard-chrome or thermal-spray coated on wear/cavitation zones.
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 1.4421 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- GX4CrNi16-4
How much does 1.4421 cost?
1.4421 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.
1.4421 — frequently asked
What is 1.4421 used for?
1.4421 is typically used for hydraulic turbine components, pump casings and impellers and general corrosion-resistant castings. In short: weldable martensitic casting; molybdenum-free 16Cr-4Ni; better corrosion than 13Cr-4Ni.
What is the yield strength of 1.4421?
1.4421 has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 850 MPa (123 ksi) — stronger than 88% of stainless steel grades. Strength varies by condition: see the 2 listed tempers.
Is 1.4421 easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine after tempering with rigid setups, sharp carbide tooling, moderate speed and heavy positive feed to avoid work hardening; the tough martensite makes chips stringy and drives insert notch wear.
Can 1.4421 be welded?
Yes — weldability is rated very good (72/100). Very good for a martensitic grade: use matching 16-5 or 13-4 low-carbon consumables, preheat/interpass 100–160 °C, avoid excessive heat input, then post-weld temper below the original tempering temperature.
What surface finishes work on 1.4421?
Passivate after machining and grinding to restore the chromium oxide film; takes a fine ground/polished finish, and can be hard-chrome or thermal-spray coated on wear/cavitation zones.
Can 1.4421 be formed, bent or molded?
Supplied as a casting — no cold forming; ensure directional solidification with adequate risering and hot isostatic pressing or weld repair for critical pressure/cavitation surfaces.
What is the maximum service temperature of 1.4421?
1.4421 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 1.4421 cost?
1.4421 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 10283 — Corrosion resistant steel castings — CEN (2010)
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Castings Handbook (soft martensitic CA6NM-type alloys) — Steel Founders' Society of America (1995)
- Stainless steel foundry datasheets for GX4CrNi13-4 / GX4CrNi16-4 castings — various European foundries (2022)
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.