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Steel P2-ANN (Annealed)

Heat-treated state · default condition

AISI/SAE P2 · UNS T51602

Standard stock condition: soft enough for cold hobbing of cavities and easy machining before carburizing.

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Values for the ANN condition

Other P2 tempers and conditions

P2 is listed in 4 conditions; see the grade overview at P2.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
ANNDefaultThis page
Annealed
Standard stock condition: soft enough for cold hobbing of cavities and easy machining before carburizing.33051027110 HB40 W/m·K
Normalized
Used to refine grain and homogenize forged or heavily machined blocks before carburizing; slightly stronger and harder than annealed.40060022150 HB—
Quenched and tempered
Direct hardening without carburizing, or the core condition of a case-hardened part; low carbon limits hardness to roughly 20–30 HRC.6208301725 HRC—
Carburized and hardened
Working condition for finished mold cavities: carburize 900–925 °C, oil quench from 790–830 °C, temper 175–200 °C for a hard wear surface on a tough core.7209501361 HRC38 W/m·K

What is P2-ANN?

P2-ANN is P2 heat treated to ANN — standard stock condition: soft enough for cold hobbing of cavities and easy machining before carburizing. P2-ANN has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 78% of steel grades. Elongation at break is 27% and the elastic modulus is 205 GPa (29.7 Msi). P2-ANN has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).

Advantages

  • Easy to machine — 70/100, better than 96% of steel grades
  • Polishes to a fine finish — 75/100, better than 94% of steel grades
  • Ductile — tolerates forming and impact — 27%, better than 86% of steel grades
  • Forms and bends easily — 70/100, better than 86% of steel grades

Limitations

  • Low strength — 330 MPa (47.9 ksi), worse than 78% of steel grades

P2-ANN properties

Typical room-temperature values for P2-ANN; 20 are specific to this condition. Other listed values are P2 reference data and may not represent this condition. Bars are the position among steel grades.

Physical3

P2-ANN has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).

Density7.85 g/cm³0.28 lb/in³
Melting Point (Solidus)1,420°C2,588 °F
Liquidus Temperature1,500°C2,732 °F

Mechanical16

P2-ANN has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 78% of steel grades. Elongation at break is 27% and the elastic modulus is 205 GPa (29.7 Msi).

Elastic (Young's) Modulus205 GPa29.7 Msi
Shear Modulus80 GPa11.6 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.29
Tensile Strength (Ultimate)510 MPa74 ksi
Yield Strength (0.2% offset)330 MPa47.9 ksi
Elongation at Break27%
Reduction in Area58%
Compressive Strength340 MPa49.3 ksi
Shear Strength330 MPa47.9 ksi
Fatigue Strength (Endurance Limit)230 MPa33.4 ksi
Fracture Toughness (K_IC)100 MPa·√m91 ksi·√in
Charpy V-Notch Impact (RT)110 J81.1 ft·lbf
Hardness, Brinell110 HB
Hardness, Rockwell B63 HRB
Hardness, Vickers115 HV

Thermal6

P2-ANN is rated for continuous service to 400°C (752 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).

Thermal Conductivity40 W/m·K23.1 BTU/hr·ft·°F
Specific Heat Capacity460 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)12.4 µm/m·K6.9 µin/in·°F
Latent Heat of Fusion250 J/g107 BTU/lb
Max Service Temperature (continuous)400°C752 °F
Min Service Temperature-20°C-4 °F

Electrical3

P2-ANN conducts electricity at 8.5 % IACS, better than 63% of steel grades.

Electrical Conductivity8.5 % IACS
Electrical Resistivity2×10⁻⁷ Ω·m7.87 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental3

Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.

Galvanic Potential (seawater, vs SCE)-0.61 V
Corrosion ResistanceNot recommended12/100
Chemical Resistance SummaryNo inherent corrosion resistance: rusts in humid air and attacked by acids, chlorides and corrosive polymer off-gases (PVC, POM, flame-retarded resins); protect with oil, chrome or nickel plating.

Sustainability4

Producing a kilogram of P2-ANN takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 35%.

Embodied Energy (primary production)34 MJ/kg14,617 BTU/lb
Embodied Carbon (primary production)2.4 kg CO₂/kg
Embodied Water60 L/kg7.2 gal/lb
Typical Recycled Content35%

Manufacturability8

P2-ANN's machinability is very good (70/100, better than 96% of steel grades); weldability good (60/100); formability very good (70/100).

MachinabilityVery good70/100
Machinability Rating (AISI 1212 = 100 %)65%
WeldabilityGood60/100
Formability (cold)Very good70/100
CastabilityFair35/100
Brazeability / SolderabilityGood55/100
PolishabilityVery good75/100
Anodizing Responsen/a — ferrous alloy; use chrome or electroless nickel plating instead

Common Calculations5

Specific Strength (UTS / density)calculated65 kN·m/kg
Specific Stiffness (E / density)calculated26.1 MN·m/kg
Modulus of Resiliencecalculated266 kJ/m³
Thermal Diffusivitycalculated11.1 mm²/s
Thermal Shock Resistance Indexcalculated8

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

Working with P2-ANN

Is P2 easy to machine?

Machine in the annealed state with sharp, positive-rake tools and generous coolant — the soft low-carbon matrix tends to smear and build up on edges; finish grind after case hardening.

Can P2 be welded?

Repair-weldable with matching low-alloy or Ni-based filler at 200–300 °C preheat, followed by re-annealing or re-carburizing; welding after case hardening risks case cracking.

Can P2 be formed, bent or molded?

Its main advantage is cold hobbing/hubbing of cavity detail in the annealed state, with intermediate anneals between hobbing passes.

What surface finishes work on P2?

Carburized surfaces take a fine mold polish or texture; hard chrome or electroless nickel plating is normal for corrosive resins and rust protection in storage.

P2 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
Cvery low carbon for hobbing and carburizing≤ 0.10.07
Mn0.1 – 0.40.25
Si0.1 – 0.40.25
Cr0.75 – 1.251
Ni0.1 – 0.50.3
Mo0.15 – 0.40.25
Pimpurity limit≤ 0.03—
Simpurity limit≤ 0.03—
Febalance—

P2-ANN — frequently asked

What is P2-ANN used for?

P2-ANN is typically used for carburized cavity inserts, small precision mold cores and plastic injection mold components requiring case hardening. In short: carburizing mold steel; cold-hobbable cavity blank; tough core, hard case.

What is the yield strength of P2-ANN?

P2-ANN has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 510 MPa (74 ksi) — weaker than 78% of steel grades. Strength varies by condition: see the 4 listed tempers.

Is P2-ANN easy to machine?

Yes — machinability is rated very good (70/100, better than 96% of steel grades). Machine in the annealed state with sharp, positive-rake tools and generous coolant — the soft low-carbon matrix tends to smear and build up on edges; finish grind after case hardening.

Can P2-ANN be welded?

Yes — weldability is rated good (60/100). Repair-weldable with matching low-alloy or Ni-based filler at 200–300 °C preheat, followed by re-annealing or re-carburizing; welding after case hardening risks case cracking.

What surface finishes work on P2-ANN?

Carburized surfaces take a fine mold polish or texture; hard chrome or electroless nickel plating is normal for corrosive resins and rust protection in storage.

Can P2-ANN be formed, bent or molded?

Its main advantage is cold hobbing/hubbing of cavity detail in the annealed state, with intermediate anneals between hobbing passes.

What is the maximum service temperature of P2-ANN?

P2-ANN is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between P2-ANN and P2-CH?

ANN is the default condition — standard stock condition: soft enough for cold hobbing of cavities and easy machining before carburizing. CH: working condition for finished mold cavities: carburize 900–925 °C, oil quench from 790–830 °C, temper 175–200 °C for a hard wear surface on a tough core. Yield strength is 330 MPa in ANN versus 720 MPa in CH.

Sources

  1. ASTM A681 — Standard Specification for Tool Steels Alloy (P-type mold steels) — ASTM International (2015)
  2. ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
  3. ASM Handbook Vol.4: Heat Treating (Tool Steels, Carburizing) — ASM International (1991)
  4. ASM Handbook Vol.16: Machining — ASM International (1989)
  5. Tool Steels, 5th edition — ASM International (Roberts, Krauss, Kennedy) (1998)

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.