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Stainless Steel 1.4305 +AT+P

Finish state

EN 1.4305 · UNS S30300 · AISI/SAE 303 · JIS SUS303 · GB Y1Cr18Ni9

+AT+P = +AT, peeled / centreless-ground bright bar

Annealed bar turned/ground to close diameter tolerance — pick when the outside diameter is used as-supplied on CNC parts.

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Request a quote in 1.4305 +AT+P1.4305 overview

Values for the +AT+P condition

Other 1.4305 tempers and conditions

1.4305 is listed in 5 conditions; see the grade overview at 1.4305.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
+ATDefault
Solution annealed
Standard stock condition for hot-rolled/peeled and centreless-ground bar; maximum corrosion resistance and ductility, softest chips.26062048160 HB—
+AT+PThis page
+AT, peeled / centreless-ground bright bar
Annealed bar turned/ground to close diameter tolerance — pick when the outside diameter is used as-supplied on CNC parts.26562045165 HB2.4 % IACS
+C700
Cold drawn, Rm ≥ 700 MPa
Light cold-drawn bar: the usual automatic-lathe stock — straight, bright, better chip control and higher strength than +AT.52076025230 HB—
+C800
Cold drawn, Rm ≥ 800 MPa
Harder cold-drawn bar for shafts, pins and fasteners needing higher proof strength and the cleanest possible turned finish.6408601626 HRC—
+C900
Cold drawn, Rm ≥ 900 MPa
Heavily drawn small-diameter bar/wire where maximum strength and stiffness of the blank matter more than ductility.7409601030 HRC—

What is 1.4305 +AT+P?

1.4305 +AT+P is 1.4305 supplied in the +AT+P condition — annealed bar turned/ground to close diameter tolerance — pick when the outside diameter is used as-supplied on CNC parts. 1.4305 +AT+P has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 81% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi). 1.4305 +AT+P 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). +AT is the default condition FabDigit quotes; +AT+P is available on request or by drawing note.

Advantages

  • Easy to machine — 60/100, better than 98% of stainless steel grades
  • Ductile — tolerates forming and impact — 45%, better than 76% of stainless steel grades

Limitations

  • Hard to polish — 45/100, worse than 96% of stainless steel grades
  • Difficult to weld — 22/100, worse than 94% of stainless steel grades
  • Low strength — 265 MPa (38.4 ksi), worse than 81% of stainless steel grades

1.4305 +AT+P properties

Typical room-temperature values for 1.4305 +AT+P; 23 are specific to this condition. Other listed values are 1.4305 reference data and may not represent this condition. Bars are the position among stainless steel grades.

Physical3

1.4305 +AT+P 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).

Density7.9 g/cm³0.29 lb/in³
Melting Point (Solidus)1,400°C2,552 °F
Liquidus Temperature1,450°C2,642 °F

Mechanical14

1.4305 +AT+P has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 81% of stainless steel grades. Elongation at break is 45% and the elastic modulus is 193 GPa (28 Msi).

Elastic (Young's) Modulus193 GPa28 Msi
Shear Modulus77 GPa11.2 Msi
Bulk Modulus140 GPa20.3 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)620 MPa89.9 ksi
Yield Strength (0.2% offset)265 MPa38.4 ksi
Elongation at Break45%
Reduction in Area55%
Shear Strength400 MPa58 ksi
Fatigue Strength (Endurance Limit)250 MPa36.3 ksi
Charpy V-Notch Impact (RT)55 J40.6 ft·lbf
Hardness, Brinell165 HB
Hardness, Rockwell B85 HRB
Hardness, Vickers175 HV

Thermal6

1.4305 +AT+P is rated for continuous service to 700°C (1,292 °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).

Thermal Conductivity16.2 W/m·K9.4 BTU/hr·ft·°F
Specific Heat Capacity500 J/kg·K0.12 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)16.5 µm/m·K9.2 µin/in·°F
Latent Heat of Fusion275 J/g118 BTU/lb
Max Service Temperature (continuous)700°C1,292 °F
Min Service Temperature-100°C-148 °F

Electrical3

1.4305 +AT+P conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.

Electrical Conductivity2.4 % IACS
Electrical Resistivity7.2×10⁻⁷ Ω·m28.3 µΩ·in
Magnetic Responseessentially non-magnetic; thin cold-worked surface layer may respond slightly

Chemical & Environmental3

Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.

Galvanic Potential (seawater, vs SCE)-0.1 V
Corrosion ResistanceGood60/100
Chemical Resistance SummaryGood in fresh water, mild atmospheres, many organic acids and food contact when passivated; distinctly poorer than 304 in chlorides (pitting/crevice attack at sulphide inclusions), and not for reducing acids, seawater or hot chloride solutions.

Sustainability4

Producing a kilogram of 1.4305 +AT+P takes about 54 MJ of energy and emits 4.5 kg of CO₂ — less than 59% of stainless steel grades. Typical recycled content is 70%.

Embodied Energy (primary production)54 MJ/kg23,216 BTU/lb
Embodied Carbon (primary production)4.5 kg CO₂/kg
Embodied Water150 L/kg18 gal/lb
Typical Recycled Content70%

Manufacturability7

1.4305 +AT+P's machinability is good (60/100, better than 98% of stainless steel grades); weldability poor (22/100); formability fair (40/100).

MachinabilityGood60/100
Machinability Rating (AISI 1212 = 100 %)70%
WeldabilityPoor22/100
Formability (cold)Fair40/100
Brazeability / SolderabilityFair45/100
PolishabilityFair45/100
Anodizing Responsen/a — stainless steel is not anodized; passivation (ASTM A967 nitric/citric) or electropolishing is used instead

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with 1.4305 +AT+P

Is 1.4305 easy to machine?

The benchmark free-machining stainless: run 60–100 m/min HSS or 150–250 m/min carbide with sharp positive-rake tools, good chip flow and generous coolant; expect ~1.5–2× the material removal rate of 304 with far better tool life.

Can 1.4305 be welded?

Not recommended — 0.15–0.35 % S promotes solidification (hot) cracking; if unavoidable, use 308L/309L filler, low heat input, no filler-free autogenous welds, and accept reduced corrosion resistance.

Can 1.4305 be formed, bent or molded?

Limited cold formability: gentle bends with large radii only, avoid heavy heading, thread rolling or deep drawing; hot work 1150–1250 °C then solution anneal 1010–1120 °C and water quench.

What surface finishes work on 1.4305?

Passivate per ASTM A967 (citric or nitric) after machining to remove smeared sulphides; electroplating and PVD work with proper activation, but mirror polishing and electropolishing reveal sulphide pits — use 304/316 if cosmetic finish is critical.

1.4305 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.

ElementSpec limit (wt %)Nominal
CEN 10088-3 max≤ 0.10.06
Si≤ 10.5
Mncombines with S as MnS chip breakers≤ 21.3
P≤ 0.050.03
Sintentional free-machining addition0.15 – 0.350.25
Cr17 – 1918
Ni8 – 109
Cu≤ 10.4
Mooptional/residual (AISI 303 allows ≤0.60 %)≤ 0.6—
Nresidual limit per EN 10088-3≤ 0.110.04
Febalance—

1.4305 +AT+P — frequently asked

What is 1.4305 +AT+P used for?

1.4305 +AT+P is typically used for precision turned fittings, fasteners and valve components. In short: best-machining austenitic stainless; not recommended for welding; turning-optimised 304 variant.

What is the yield strength of 1.4305 +AT+P?

1.4305 +AT+P has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 81% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.

Is 1.4305 +AT+P easy to machine?

Reasonably — machinability is rated good (60/100, better than 98% of stainless steel grades). The benchmark free-machining stainless: run 60–100 m/min HSS or 150–250 m/min carbide with sharp positive-rake tools, good chip flow and generous coolant; expect ~1.5–2× the material removal rate of 304 with far better tool life.

Can 1.4305 +AT+P be welded?

Not readily — weldability is rated poor (22/100). Not recommended — 0.15–0.35 % S promotes solidification (hot) cracking; if unavoidable, use 308L/309L filler, low heat input, no filler-free autogenous welds, and accept reduced corrosion resistance.

What surface finishes work on 1.4305 +AT+P?

Passivate per ASTM A967 (citric or nitric) after machining to remove smeared sulphides; electroplating and PVD work with proper activation, but mirror polishing and electropolishing reveal sulphide pits — use 304/316 if cosmetic finish is critical.

Can 1.4305 +AT+P be formed, bent or molded?

Limited cold formability: gentle bends with large radii only, avoid heavy heading, thread rolling or deep drawing; hot work 1150–1250 °C then solution anneal 1010–1120 °C and water quench.

What is the maximum service temperature of 1.4305 +AT+P?

1.4305 +AT+P is rated for continuous use to about 700°C (1,292 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

Sources

  1. EN 10088-3 Stainless steels — Technical delivery conditions for semi-finished products, bars, rods, wire, sections — CEN (2014)
  2. ASTM A582/A582M Free-Machining Stainless Steel Bars — ASTM (2021)
  3. GB/T 1220 — SAC (2007)
  4. JIS G 4303 Stainless steel bars (SUS303) — JSA (2012)
  5. ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
  6. Outokumpu / Sandvik free-machining austenitic bar datasheets (4305 / 303) — Outokumpu; Sandvik (2023)
  7. (SMM) / Mysteel — SMM; Mysteel (2026)

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.