Stainless Steel 1.4948-AT
Precip hard · default condition
EN 1.4948
Standard delivery condition for plate, tube, bar and forgings; best corrosion resistance and ductility, the condition covered by EN 10028-7 / ASME code values.
Values for the AT condition
Other 1.4948 tempers and conditions
1.4948 is listed in 6 conditions; see the grade overview at 1.4948.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Forged + solution annealed (EN 10222-5 forgings) | Flanges, valve bodies and headers forged then solution annealed; slightly lower guaranteed properties in heavy sections. | 245 | 570 | 48 | 145 HB | 2.4 % IACS |
ATDefaultThis page solution annealed (~1050 °C, water quenched) | Standard delivery condition for plate, tube, bar and forgings; best corrosion resistance and ductility, the condition covered by EN 10028-7 / ASME code values. | 260 | 590 | 52 | 150 HB | — |
Cold drawn | Choose for straight, close-tolerance bar and instrument tubing where higher yield and better chip control than annealed are wanted. | 450 | 700 | 30 | 16 HRC | 2.4 % IACS |
Quarter hard | Cold-rolled temper for springy or higher-strength structural sheet parts that are not exposed to sensitising temperatures. | 570 | 900 | 12 | 25 HRC | 2.4 % IACS |
Half hard | Higher-strength cold-rolled temper for clamps, straps and stampings with only mild bending. | 800 | 1,070 | 8 | 32 HRC | 2.4 % IACS |
Full hard | Maximum cold-rolled strength for flat springs and shims; essentially no formability and strongly ferromagnetic from deformation martensite. | 1,010 | 1,320 | 4 | 41 HRC | 2.3 % IACS |
What is 1.4948-AT?
1.4948-AT is 1.4948 in the AT condition — standard delivery condition for plate, tube, bar and forgings; best corrosion resistance and ductility, the condition covered by EN 10028-7 / ASME code values. 1.4948-AT has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 52% and the elastic modulus is 200 GPa (29 Msi). 1.4948-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
- Tough — resists crack growth — 220 MPa·√m (200.2 ksi·√in), better than 97% of stainless steel grades
- Ductile — tolerates forming and impact — 52%, better than 95% of stainless steel grades
- Forms and bends easily — 85/100, better than 95% 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 — 260 MPa (37.7 ksi), worse than 84% of stainless steel grades
1.4948-AT properties
Typical room-temperature values for 1.4948-AT; 11 are specific to this condition. Other listed values are 1.4948 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4948-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
1.4948-AT has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 52% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1.4948-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 µm/m·K (8.89 µin/in·°F).
Electrical3
1.4948-AT 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 1.4948-AT 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
1.4948-AT's machinability is fair (40/100, better than 72% of stainless steel grades); weldability excellent (85/100); formability excellent (85/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4948-AT
Is 1.4948 easy to machine?
Gummy and work-hardening — use rigid setups, sharp positive-rake carbide, heavy constant feed, high-pressure coolant; ~45% of AISI 1212.
Can 1.4948 be welded?
Readily welded by GTAW/GMAW/SMAW with 308H filler to keep elevated-temperature strength; no preheat, keep interpass low, avoid prolonged 425–850 °C exposure to limit carbide sensitisation.
Can 1.4948 be formed, bent or molded?
Excellent cold formability (deep drawing, roll bending, tube bending) but high springback and rapid work hardening; hot work 1150–900 °C then solution anneal at 1040–1100 °C with rapid cooling.
What surface finishes work on 1.4948?
Pickle/passivate after welding to restore the passive film; electropolish or mechanically polish to No.4/No.8; not anodisable, plating rarely needed.
1.4948 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 |
|---|---|---|
| Ccontrolled range for creep strength | 0.04 – 0.08 | 0.06 |
| Si | ≤ 0.75 | 0.45 |
| Mn | ≤ 2 | 1.5 |
| P | ≤ 0.04 | 0.03 |
| S≤0.030 in ASTM S30409 | ≤ 0.02 | 0.01 |
| Cr | 17 – 19 | 18.2 |
| Ni | 8 – 11 | 9.3 |
| N | ≤ 0.1 | 0.05 |
| Fe | balance | — |
1.4948-AT — frequently asked
What is 1.4948-AT used for?
1.4948-AT is typically used for pressure vessels, boiler tubing, process piping, heat exchangers and food processing equipment. In short: high-temperature 304 variant; controlled carbon for creep strength; standard boiler and vessel grade.
What is the yield strength of 1.4948-AT?
1.4948-AT has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 590 MPa (85.6 ksi) — weaker than 84% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 1.4948-AT easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Gummy and work-hardening — use rigid setups, sharp positive-rake carbide, heavy constant feed, high-pressure coolant; ~45% of AISI 1212.
Can 1.4948-AT be welded?
Yes — weldability is rated excellent (85/100). Readily welded by GTAW/GMAW/SMAW with 308H filler to keep elevated-temperature strength; no preheat, keep interpass low, avoid prolonged 425–850 °C exposure to limit carbide sensitisation.
What surface finishes work on 1.4948-AT?
Pickle/passivate after welding to restore the passive film; electropolish or mechanically polish to No.4/No.8; not anodisable, plating rarely needed.
Can 1.4948-AT be formed, bent or molded?
Excellent cold formability (deep drawing, roll bending, tube bending) but high springback and rapid work hardening; hot work 1150–900 °C then solution anneal at 1040–1100 °C with rapid cooling.
What is the maximum service temperature of 1.4948-AT?
1.4948-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.
What is the difference between 1.4948-AT and 1.4948-FH?
AT is the default condition — standard delivery condition for plate, tube, bar and forgings; best corrosion resistance and ductility, the condition covered by EN 10028-7 / ASME code values. FH: maximum cold-rolled strength for flat springs and shims; essentially no formability and strongly ferromagnetic from deformation martensite. Yield strength is 260 MPa in AT versus 1,010 MPa in FH.
Sources
- EN 10028-7 Flat products for pressure purposes — stainless steels — CEN (2016)
- EN 10216-5 Seamless steel tubes for pressure purposes — stainless steels — CEN (2021)
- EN 10222-5 Steel forgings for pressure purposes — austenitic stainless — CEN (2017)
- ASTM A240/A213 (304H, S30409, TP304H) — ASTM International (2023)
- ASM Handbook Vol.1 — Properties of Stainless Steels — ASM International (1990)
- Outokumpu Steel Handbook / Core 304H (1.4948) datasheet — Outokumpu (2023)
- Sandvik 3R12H / TP304H tube datasheet — Alleima (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.