Stainless Steel 1.4640
EN 1.4640
1.4640 (X5CrNiCu19-6-2, UNS S30430, 302Cu/XM-7) is a copper-modified 18-8 austenitic stainless with a reduced work-hardening rate, engineered for severe cold-heading operations such as bolt and rivet manufacture.
Reference datasheet — 1.4640 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 A condition
1.4640 tempers and conditions
1.4640 is supplied in 8 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled | Hot-rolled and annealed rod/bar — the feedstock condition supplied to wire drawers and forgers. | 225 | 510 | 55 | 145 HB | — |
ADefault Solution annealed | Default stocked condition: soft, maximum ductility for multi-station cold heading of bolts, screws and rivets. | 240 | 520 | 55 | 150 HB | — |
Cold Rolled, annealed & pickled | Cold-rolled soft strip for deep-drawn and stamped parts where a bright, dimensionally accurate surface is needed. | 255 | 540 | 52 | 155 HB | — |
Cold drawn | Annealed-and-drawn CHQ wire with coating (soap/lime or oxalate) — the normal input for header machines and for as-drawn shafts. | 450 | 620 | 30 | 92 HRB | — |
Finished fastener, property class A2-70 | As-delivered bolts/screws headed from this grade, meeting ISO 3506-1 A2-70 strength requirements. | 480 | 730 | 15 | 21 HRC | 2.4 % IACS |
Quarter hard | Light temper rolling/drawing for springy clips and fasteners needing higher proof load with retained bendability. | 520 | 780 | 20 | 23 HRC | 2.4 % IACS |
Half hard | Medium temper for flat springs, washers and formed strip parts where strength dominates over deep forming. | 720 | 950 | 12 | 30 HRC | 2.4 % IACS |
Full hard | Maximum cold-worked strength for wire forms and springs; bending must be across the rolling/drawing direction. | 950 | 1,150 | 6 | 36 HRC | 2.3 % IACS |
What is 1.4640?
1.4640 (X5CrNiCu19-6-2, UNS S30430, 302Cu/XM-7) is a copper-modified 18-8 austenitic stainless with a reduced work-hardening rate, engineered for severe cold-heading operations such as bolt and rivet manufacture. It is supplied mainly as CHQ wire and cold-drawn bar from annealed and 2B strip through quarter-hard, half-hard and full-hard tempers, including property class A2-70, at 240 MPa yield, 520 MPa tensile, 55 % elongation and 150 HB (78 HRB) with formability rated 95. Machinability is no better than 304 and no free-machining variant exists, while copper and low delta ferrite raise hot-cracking risk; use 1.4650 (X2CrNiCu19-10) when parts must be welded. 1.4640 has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F). 1.4640 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
What is 1.4640 used for?
- cold-headed screws
- rivets
- wire fasteners
Advantages
- Forms and bends easily — 95/100, better than 99% of stainless steel grades
- Ductile — tolerates forming and impact — 55%, better than 97% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
- Tough — resists crack growth — 200 MPa·√m (182 ksi·√in), better than 86% of stainless steel grades
Limitations
- Low strength — 240 MPa (34.8 ksi), worse than 96% of stainless steel grades
1.4640 properties
Typical room-temperature values for 1.4640-A; bars are the position among stainless steel grades.
Physical3
1.4640 has a density of 7.9 g/cm³ (0.285 lb/in³), heavier than 68% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4640 has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
1.4640 is rated for continuous service to 750°C (1,382 °F). It conducts heat at 16.2 W/m·K (9.36 BTU/hr·ft·°F), better than 64% of stainless steel grades. Thermal expansion is 16.5 µm/m·K (9.17 µin/in·°F).
Electrical3
1.4640 conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 52% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4640 takes about 53 MJ of energy and emits 5.2 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 65%.
Manufacturability7
1.4640's machinability is fair (40/100, better than 72% of stainless steel grades); weldability very good (70/100); formability excellent (95/100).
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. 1.4640 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 1.4640
Is 1.4640 easy to machine?
Gummy and work-hardening like 304 (≈45% of AISI 1212) — use sharp positive-rake carbide, heavy constant feed, no dwelling, and flood coolant; free-machining variants are not available in this Cu grade.
Can 1.4640 be welded?
Weldable by GTAW/GMAW/resistance methods with 308L/347 filler, but the low delta-ferrite and copper content raise hot-cracking risk, so keep heat input low and avoid autogenous welds on heavily restrained joints.
Can 1.4640 be formed, bent or molded?
Outstanding cold formability — designed for 4–6 station cold heading, thread rolling and deep drawing with much lower heading pressure and die wear than 302/304; solution anneal at 1040–1100 °C and water quench between severe operations.
1.4640 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≤0.10 in some national grades | ≤ 0.08 | 0.05 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.05 | 0.03 |
| Skept low for cold heading | ≤ 0.03 | 0.01 |
| Cr | 17 – 19 | 18 |
| Ni | 8 – 10 | 9 |
| Cuthe defining addition: lowers work-hardening rate | 3 – 4 | 3.5 |
| Nkept low to aid heading | ≤ 0.05 | 0.03 |
| Fe | balance |
What surface finishes work on 1.4640?
Passivate per ASTM A967 (nitric or citric) after heading; electropolishing and mechanical polishing give a bright finish, and zinc/PTFE or Ni coatings are used only where galling or galvanic isolation is required.
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 1.4640 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- X5CrNiCu19-6-2
- Similar grades
- S30430
How much does 1.4640 cost?
1.4640 is a standard-cost stainless steel ($$), cheaper than about 71% 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.
1.4640 — frequently asked
What is 1.4640 used for?
1.4640 is typically used for cold-headed screws, rivets and wire fasteners. In short: best-heading 18-8 stainless; copper-lowered work hardening; weld with care only.
What is the yield strength of 1.4640?
1.4640 has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 520 MPa (75.4 ksi) — weaker than 96% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is 1.4640 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Gummy and work-hardening like 304 (≈45% of AISI 1212) — use sharp positive-rake carbide, heavy constant feed, no dwelling, and flood coolant; free-machining variants are not available in this Cu grade.
Can 1.4640 be welded?
Yes — weldability is rated very good (70/100). Weldable by GTAW/GMAW/resistance methods with 308L/347 filler, but the low delta-ferrite and copper content raise hot-cracking risk, so keep heat input low and avoid autogenous welds on heavily restrained joints.
What surface finishes work on 1.4640?
Passivate per ASTM A967 (nitric or citric) after heading; electropolishing and mechanical polishing give a bright finish, and zinc/PTFE or Ni coatings are used only where galling or galvanic isolation is required.
Can 1.4640 be formed, bent or molded?
Outstanding cold formability — designed for 4–6 station cold heading, thread rolling and deep drawing with much lower heading pressure and die wear than 302/304; solution anneal at 1040–1100 °C and water quench between severe operations.
What is the maximum service temperature of 1.4640?
1.4640 is rated for continuous use to about 750°C (1,382 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4640-A and 1.4640-FH?
A is the default condition — default stocked condition: soft, maximum ductility for multi-station cold heading of bolts, screws and rivets. FH: maximum cold-worked strength for wire forms and springs; bending must be across the rolling/drawing direction. Yield strength is 240 MPa in A versus 950 MPa in FH.
How much does 1.4640 cost?
1.4640 is a standard-cost stainless steel ($$), cheaper than about 71% 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
- ASTM A493 — Stainless Steel Wire and Wire Rod for Cold Heading and Cold Forging (XM-7 / S30430) — ASTM International (2023)
- EN 10088-3 — Stainless steels: technical delivery conditions for semi-finished products, bars, rods — CEN (2014)
- ISO 3506-1 — Fasteners: mechanical properties of corrosion-resistant stainless steel fasteners (A2 group) — ISO (2020)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Cold heading quality austenitic wire (302HQ/S30430) product data — Sandvik / Outokumpu (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.