Stainless Steel 1.4578-FH (Full hard)
Supply condition
EN 1.4578
Maximum-strength spring/clip wire; almost no further forming and reduced SCC margin.
Values for the FH condition
Other 1.4578 tempers and conditions
1.4578 is listed in 7 conditions; see the grade overview at 1.4578.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Default stock condition: maximum ductility for cold heading, deep drawing and multi-stage forming. | 235 | 540 | 45 | 150 HB | — |
soft annealed, lightly drawn / coated cold-heading quality wire | Pick for high-volume cold-headed fasteners: annealed wire with light sizing pass and forming lubricant/coating. | 280 | 570 | 40 | 165 HB | 2.3 % IACS |
cold drawn, tensile class 700 MPa min (≈1/4 hard) | Light cold draw for straight, dimensionally accurate bar with moderate strength gain and retained bendability. | 480 | 760 | 22 | 18 HRC | 2.3 % IACS |
cold drawn, tensile class 800 MPa min | Medium cold-drawn bar/wire for shafts and pins where 316-class corrosion plus higher proof strength is needed. | 600 | 860 | 16 | 24 HRC | 2.3 % IACS |
cold drawn, tensile class 900 MPa min (≈1/2 hard) | Choose when spring-back stiffness and higher load capacity matter more than further forming. | 700 | 950 | 12 | 28 HRC | 2.3 % IACS |
cold drawn, tensile class 1000 MPa min (≈3/4 hard) | Heavily drawn wire for high-strength fasteners, clips and springs in mildly corrosive service. | 830 | 1,060 | 10 | 31 HRC | 2.3 % IACS |
FHThis page Full hard | Maximum-strength spring/clip wire; almost no further forming and reduced SCC margin. | 1,000 | 1,250 | 6 | 36 HRC | — |
What is 1.4578-FH?
1.4578-FH is 1.4578 supplied in the FH condition — maximum-strength spring/clip wire; almost no further forming and reduced SCC margin. 1.4578-FH has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,250 MPa (181 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 195 GPa (28.3 Msi). 1.4578-FH has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,385°C (2,525 °F). A is the default condition FabDigit quotes; FH is available on request or by drawing note.
Advantages
- High strength — 1,000 MPa (145 ksi), better than 98% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
Limitations
- Limited ductility — 6%, worse than 99% of stainless steel grades
- Limited formability — 15/100, worse than 91% of stainless steel grades
- Limited service temperature — 300°C (572 °F), worse than 90% of stainless steel grades
- Low fracture toughness — 85 MPa·√m (77.4 ksi·√in), worse than 77% of stainless steel grades
1.4578-FH properties
Typical room-temperature values for 1.4578-FH; 19 are specific to this condition. Other listed values are 1.4578 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4578-FH has a density of 8 g/cm³ (0.289 lb/in³), heavier than 92% of stainless steel grades. It melts at 1,385°C (2,525 °F).
Mechanical16
1.4578-FH has a yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,250 MPa (181 ksi) — stronger than 98% of stainless steel grades. Elongation at break is 6% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4578-FH is rated for continuous service to 300°C (572 °F). It conducts heat at 15 W/m·K (8.67 BTU/hr·ft·°F), worse than 59% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.4578-FH conducts electricity at 2.3 % IACS, better than 55% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (69/100), better than 66% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4578-FH takes about 55 MJ of energy and emits 5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
1.4578-FH's machinability is fair (36/100, better than 57% of stainless steel grades); weldability good (55/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4578-FH
Is 1.4578 easy to machine?
Machines like 316L — gummy, work-hardening chips; use sharp positive-rake carbide, rigid setup, 60–110 m/min, heavy feed and flood coolant, avoid dwelling; Cu gives marginally better chip breaking than 1.4404.
Can 1.4578 be welded?
Weldable by TIG/MIG/resistance with 316L or 316LSi filler, no preheat, low heat input and fast cooling; the ~3 % Cu raises hot-cracking sensitivity so keep interpass temperature and dilution low and avoid heavy restraint.
Can 1.4578 be formed, bent or molded?
The reason to buy this grade: low work-hardening rate allows multi-stage cold heading, thread rolling and deep drawing with lower press loads; still needs good lubrication, chrome-free tooling coatings and interstage annealing only for extreme upsets.
What surface finishes work on 1.4578?
Passivate (ASTM A967 nitric/citric) or electropolish after forming to restore the chromium oxide; takes a bright mechanical polish, can be PVD-coated or blackened, but must not be anodised.
1.4578 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 weld/corrosion stability | ≤ 0.04 | 0.03 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 2 | 1.3 |
| P | ≤ 0.05 | — |
| Slow S for cold-heading ductility | ≤ 0.02 | — |
| Cr | 16 – 18 | 17 |
| Niraised Ni stabilises austenite, lowers work hardening | 10 – 12 | 11 |
| Mopitting resistance (316-class) | 1.8 – 2.5 | 2 |
| Cukey addition for cold formability | 2.5 – 3.5 | 3 |
| Nkept low to limit work hardening | ≤ 0.11 | 0.04 |
| Fe | balance | — |
1.4578-FH — frequently asked
What is 1.4578-FH used for?
1.4578-FH is typically used for cold-formed fasteners, hardware components and marine fittings. In short: cold-heading 316 variant; molybdenum corrosion with high formability; copper raises hot-cracking risk.
What is the yield strength of 1.4578-FH?
1.4578-FH has a typical yield strength of 1,000 MPa (145 ksi) and a tensile strength of 1,250 MPa (181 ksi) — stronger than 98% of stainless steel grades. Strength varies by condition: see the 7 listed tempers.
Is 1.4578-FH easy to machine?
Not especially — machinability is rated fair (36/100, better than 57% of stainless steel grades). Machines like 316L — gummy, work-hardening chips; use sharp positive-rake carbide, rigid setup, 60–110 m/min, heavy feed and flood coolant, avoid dwelling; Cu gives marginally better chip breaking than 1.4404.
Can 1.4578-FH be welded?
Yes — weldability is rated good (55/100). Weldable by TIG/MIG/resistance with 316L or 316LSi filler, no preheat, low heat input and fast cooling; the ~3 % Cu raises hot-cracking sensitivity so keep interpass temperature and dilution low and avoid heavy restraint.
What surface finishes work on 1.4578-FH?
Passivate (ASTM A967 nitric/citric) or electropolish after forming to restore the chromium oxide; takes a bright mechanical polish, can be PVD-coated or blackened, but must not be anodised.
Can 1.4578-FH be formed, bent or molded?
The reason to buy this grade: low work-hardening rate allows multi-stage cold heading, thread rolling and deep drawing with lower press loads; still needs good lubrication, chrome-free tooling coatings and interstage annealing only for extreme upsets.
What is the maximum service temperature of 1.4578-FH?
1.4578-FH is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4578-A and 1.4578-FH?
A is the default condition — default stock condition: maximum ductility for cold heading, deep drawing and multi-stage forming. FH: maximum-strength spring/clip wire; almost no further forming and reduced SCC margin. Yield strength is 235 MPa in A versus 1,000 MPa in FH.
Sources
- EN 10088-3 Stainless steels — semi-finished products, bars, rods, wire, sections — CEN (2014)
- EN 10263-5 Steel rod, bars and wire for cold heading and cold extrusion — stainless steels — CEN (2017)
- EN 10088-1 Stainless steels — list of stainless steels (physical properties) — CEN (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Cold-heading quality austenitic stainless wire (Cu-modified 316-type) datasheets — European stainless wire producers (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.