Stainless Steel 1.4303 +AT (Solution annealed)
Heat-treated state · default condition
EN 1.4303 · UNS S30500 · AISI/SAE 305 · JIS SUS305
Standard stock condition: maximum ductility and corrosion resistance for deep drawing, spinning and cold heading.
Values for the +AT condition
Other 1.4303 tempers and conditions
1.4303 is listed in 5 conditions; see the grade overview at 1.4303.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ATDefaultThis page Solution annealed | Standard stock condition: maximum ductility and corrosion resistance for deep drawing, spinning and cold heading. | 240 | 570 | 55 | 140 HB | — |
Cold worked to 700 MPa minimum tensile strength | Lightly cold-rolled strip/wire when higher strength is needed but some residual forming ductility must remain. | 450 | 760 | 30 | 220 HB | — |
Quarter hard | US-market equivalent of light cold work for 305 sheet and strip where an ASTM temper call-out is required. | 520 | 800 | 25 | 22 HRC | 2.4 % IACS |
Cold worked to 800 MPa minimum tensile strength | Harder cold-rolled condition for springs, clips and flat parts needing strength with non-magnetic behaviour. | 600 | 870 | 22 | 25 HRC | — |
Cold worked to 1000 MPa minimum tensile strength | Heavily drawn wire/strip; the practical upper strength limit for this low-hardening grade, ductility largely spent. | 800 | 1,060 | 12 | 32 HRC | 2.3 % IACS |
What is 1.4303 +AT?
1.4303 +AT is 1.4303 heat treated to +AT — standard stock condition: maximum ductility and corrosion resistance for deep drawing, spinning and cold heading. 1.4303 +AT has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 200 GPa (29 Msi). 1.4303 +AT 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).
Advantages
- Forms and bends easily — 96/100, better than 100% of stainless steel grades
- Ductile — tolerates forming and impact — 55%, better than 97% of stainless steel grades
- Tough — resists crack growth — 220 MPa·√m (200.2 ksi·√in), better than 97% of stainless steel grades
- Polishes to a fine finish — 80/100, better than 89% of stainless steel grades
- Readily welded — 85/100, better than 87% of stainless steel grades
Limitations
- Low strength — 240 MPa (34.8 ksi), worse than 96% of stainless steel grades
- High embodied carbon — 6 kg CO₂/kg, worse than 88% of stainless steel grades
1.4303 +AT properties
Typical room-temperature values for 1.4303 +AT; 15 are specific to this condition. Other listed values are 1.4303 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4303 +AT 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
1.4303 +AT has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 96% of stainless steel grades. Elongation at break is 55% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4303 +AT is rated for continuous service to 800°C (1,472 °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
1.4303 +AT conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (65/100), better than 56% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4303 +AT takes about 56 MJ of energy and emits 6 kg of CO₂ — more than 59% of stainless steel grades. Typical recycled content is 65%.
Manufacturability7
1.4303 +AT's machinability is poor (32/100, worse than 62% of stainless steel grades); weldability excellent (85/100); formability excellent (96/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4303 +AT
Is 1.4303 easy to machine?
Gummy and prone to built-up edge — use sharp, positive-rake carbide, heavy feed, rigid setup and flood coolant; expect ~40% of AISI 1212 speeds.
Can 1.4303 be welded?
Readily welded by GTAW/GMAW/resistance methods with 308L filler; no preheat, keep interpass low and avoid heavy heat input to limit sensitisation and distortion.
Can 1.4303 be formed, bent or molded?
Its low work-hardening rate gives excellent deep drawing, spinning, thread rolling and cold heading with less interstage annealing than 304.
What surface finishes work on 1.4303?
Cannot be anodized; passivate per ASTM A967 after machining, and electropolish or mechanically polish (BA/No.4/No.8) for hygienic or decorative surfaces.
1.4303 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 |
|---|---|---|
| CEN 10088; ASTM 305 allows ≤0.12 | ≤ 0.06 | 0.04 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 2 | 1.2 |
| P | ≤ 0.05 | — |
| SASTM 305 allows ≤0.030 | ≤ 0.02 | — |
| Cr | 17 – 19 | 18 |
| Nihigh Ni stabilises austenite, low work hardening | 11 – 13 | 12 |
| N | ≤ 0.11 | 0.04 |
| Fe | balance | — |
1.4303 +AT — frequently asked
What is 1.4303 +AT used for?
1.4303 +AT is typically used for cold-headed fasteners, deep-drawn parts and wire forming. In short: deep-drawing austenitic grade; lower work hardening than 304; higher nickel, higher cost.
What is the yield strength of 1.4303 +AT?
1.4303 +AT has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 570 MPa (82.7 ksi) — weaker than 96% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4303 +AT easy to machine?
Not especially — machinability is rated poor (32/100, worse than 62% of stainless steel grades). Gummy and prone to built-up edge — use sharp, positive-rake carbide, heavy feed, rigid setup and flood coolant; expect ~40% of AISI 1212 speeds.
Can 1.4303 +AT be welded?
Yes — weldability is rated excellent (85/100). Readily welded by GTAW/GMAW/resistance methods with 308L filler; no preheat, keep interpass low and avoid heavy heat input to limit sensitisation and distortion.
What surface finishes work on 1.4303 +AT?
Cannot be anodized; passivate per ASTM A967 after machining, and electropolish or mechanically polish (BA/No.4/No.8) for hygienic or decorative surfaces.
Can 1.4303 +AT be formed, bent or molded?
Its low work-hardening rate gives excellent deep drawing, spinning, thread rolling and cold heading with less interstage annealing than 304.
What is the maximum service temperature of 1.4303 +AT?
1.4303 +AT 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.
Sources
- EN 10088-1/-2/-3 Stainless steels — grade and product specifications — CEN (2014)
- ASTM A240/A666 (UNS S30500, Type 305) — 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)
- Austenitic stainless 1.4303 / 305 strip and wire datasheets — Outokumpu / Sandvik (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.