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Steel P4-ANN vs P4 HT-40HRC

Steel · P4 temper comparison

P4-ANN and P4 HT-40HRC are two conditions of the same steel grade, P4: ANN (annealed) versus HT-40HRC (hardened & tempered). The chemistry is identical, so every difference below comes from the condition. P4 HT-40HRC is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 300 MPa (43.5 ksi) for P4-ANN, about 3.5 times as much; tensile strength follows at 1,300 MPa (189 ksi) vs 500 MPa (72.5 ksi). In exchange, P4-ANN is the more ductile: elongation 25% versus 12% for P4 HT-40HRC, and P4 HT-40HRC is harder (390 HB vs 122 HB). P4-ANN runs hotter in service (400°C vs 350°C continuous). On the shop floor, P4-ANN machines more easily (good vs poor) and P4-ANN welds better (fair vs poor).

P4-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

P4 HT-40HRCChoose it when strength drives the design.

P4-ANN vs P4 HT-40HRC: properties

P4-ANNP4 HT-40HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

500 MPa72.5 ksi
1,300 MPa189 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
1,050 MPa152 ksi

Elongation at Break

25%
12%

Reduction in Area

55%
40%

Compressive Strength

320 MPa46.4 ksi
1,150 MPa167 ksi

Shear Strength

330 MPa47.9 ksi
800 MPa116 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
600 MPa87 ksi

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

122 HB
390 HB

Hardness, Vickers

128 HV
410 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 69 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

How each material carries heat and how hot it can run.

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Same in both: Thermal Conductivity 26 W/m·K15 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

20 / 100
22 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

60 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
25%

Weldability

45 / 100
25 / 100

Formability (cold)

60 / 100
10 / 100

Same in both: Castability 30 / 100 · Brazeability / Solderability 50 / 100 · Polishability 88 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleP4

P4-ANN vs P4 HT-40HRC — frequently asked

Is P4 HT-40HRC stronger than P4-ANN?

Yes. P4 HT-40HRC has a typical yield strength of 1,050 MPa (152 ksi) against 300 MPa (43.5 ksi) for P4-ANN — about 3.5 times as much. Tensile strength is 1,300 MPa (189 ksi) vs 500 MPa (72.5 ksi).

Which condition does FabDigit quote by default, ANN or HT-40HRC?

ANN is the default P4 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, P4-ANN or P4 HT-40HRC?

P4-ANN. Its machinability rates good (60/100) against poor (30/100) for P4 HT-40HRC; for welding the order is P4-ANN first (fair, 45/100) then P4 HT-40HRC (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in P4-ANN and P4 HT-40HRC side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.