Stainless Steel 304Cu · temper · default condition
Stainless Steel 304Cu Annealed
Properties of the Annealed condition, compared with the other 304Cu tempers.
Default stock condition for cold heading, riveting and deep drawing where maximum ductility is needed.
What is 304Cu Annealed?
304Cu Annealed is 304Cu in the Annealed temper — default stock condition for cold heading, riveting and deep drawing where maximum ductility is needed. 304Cu Annealed has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 100% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi). 304Cu Annealed has a density of 7.93 g/cm³ (0.286 lb/in³), heavier than 76% of stainless steel grades. It melts at 1,400°C (2,552 °F).
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 — 82/100, better than 95% of stainless steel grades
Limitations
- Low strength — 210 MPa (30.5 ksi), worse than 100% of stainless steel grades
304Cu Annealed properties
Typical room-temperature values for 304Cu Annealed — 12 properties are specific to this condition; the rest are grade-level values shared by every 304Cu temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
304Cu Annealed has a density of 7.93 g/cm³ (0.286 lb/in³), heavier than 76% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical14
304Cu Annealed has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 100% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
304Cu Annealed 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 17.3 µm/m·K (9.61 µin/in·°F).
Electrical3
304Cu Annealed conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 53% of stainless steel grades.
Sustainability4
Producing a kilogram of 304Cu Annealed takes about 55 MJ of energy and emits 4.5 kg of CO₂ — less than 51% of stainless steel grades. Typical recycled content is 65%.
Manufacturability7
304Cu Annealed's machinability is fair (42/100, better than 79% of stainless steel grades); weldability very good (72/100); 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.
Other 304Cu tempers and conditions
304Cu is also supplied in 4 other conditions. The full side-by-side table is on the 304Cu overview.
- AnnealedDefaultDefault stock condition for cold heading, riveting and deep drawing where maximum ductility is needed.210 MPa yield · 145 HB
- 1/4 HardUse when a modest strength increase is needed but the part still has to be bent or roll-formed.550 MPa yield · 25 HRC
- Cold DrawnPick for wire and bar that must hold size and give higher strength while still allowing moderate forming or threading.520 MPa yield · 20 HRC
Working with 304Cu Annealed
Is 304Cu easy to machine?
Gummy and work-hardening like 304 — use sharp, positive-rake carbide, heavy feed, rigid setup and flood coolant; avoid dwelling to prevent a hardened skin.
Can 304Cu be welded?
Weldable by GTAW/GMAW/resistance methods with 308L filler; keep heat input low and avoid hot-crack-prone dilution because copper widens the solidification range.
Can 304Cu be formed, bent or molded?
Excellent for multi-station cold heading, upsetting and deep drawing thanks to the low work-hardening rate; anneal between severe reductions and use chloride-free lubricants.
What surface finishes work on 304Cu?
Passivate (nitric or citric) after forming, or electropolish for best appearance; mechanically polishes well to a bright finish, and no anodizing is applicable.
304Cu 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 |
|---|---|---|
| Csome mills hold ≤0.06 for better formability | ≤ 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 |
| Culowers work-hardening rate | 3 – 4 | 3.4 |
| Fe | balance | — |
304Cu Annealed — frequently asked
What is 304Cu Annealed used for?
304Cu Annealed is typically used for cold-headed screws and bolts, drawn enclosures, cookware liners, stainless rivets, deep-drawn cups and shells and sink bowls. In short: cold-heading copper-bearing stainless.
What is the yield strength of 304Cu Annealed?
304Cu Annealed has a typical yield strength of 210 MPa (30.5 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 100% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 304Cu Annealed easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Gummy and work-hardening like 304 — use sharp, positive-rake carbide, heavy feed, rigid setup and flood coolant; avoid dwelling to prevent a hardened skin.
Can 304Cu Annealed be welded?
Yes — weldability is rated very good (72/100). Weldable by GTAW/GMAW/resistance methods with 308L filler; keep heat input low and avoid hot-crack-prone dilution because copper widens the solidification range.
What surface finishes work on 304Cu Annealed?
Passivate (nitric or citric) after forming, or electropolish for best appearance; mechanically polishes well to a bright finish, and no anodizing is applicable.
Can 304Cu Annealed be formed, bent or molded?
Excellent for multi-station cold heading, upsetting and deep drawing thanks to the low work-hardening rate; anneal between severe reductions and use chloride-free lubricants.
What is the maximum service temperature of 304Cu Annealed?
304Cu Annealed 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.
Can FabDigit make parts in 304Cu Annealed?
Yes — 304Cu Annealed is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A493 — Stainless Steel Wire and Wire Rods for Cold Heading and Cold Forging — ASTM (2022)
- ASTM A314 / UNS S30430 (XM-7) chemistry — ASTM (2021)
- GB/T 1220 / 06Cr18Ni9Cu3 — SAC (2007)
- ISO 3506-1 Fasteners — Stainless steel, property class A2-70 — ISO (2020)
- ASM Handbook Vol.1 — Properties of Wrought Stainless Steels — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion of Stainless Steels — ASM International (2005)
- 302HQ / S30430 cold-heading wire datasheet — Sandvik / Suzuki Garphyttan (2021)
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.