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Steel HP9-4-20-ANN vs HP9-4-20 N+T

Steel · HP9-4-20 temper comparison

HP9-4-20-ANN and HP9-4-20 N+T are two conditions of the same steel grade, HP9-4-20: ANN (annealed) versus N+T (normalized and tempered). The chemistry is identical, so every difference below comes from the condition. HP9-4-20 N+T is the stronger of the two: yield strength 930 MPa (135 ksi) against 760 MPa (110 ksi) for HP9-4-20-ANN, about 22% more; tensile strength follows at 1,100 MPa (160 ksi) vs 965 MPa (140 ksi). HP9-4-20 N+T is harder — 320 HB against 280 HB for HP9-4-20-ANN — which matters for wear surfaces and threads. On the shop floor, HP9-4-20-ANN forms better (fair vs poor).

HP9-4-20 N+TChoose it when strength drives the design, or when surface hardness matters.

HP9-4-20-ANN vs HP9-4-20 N+T: properties

HP9-4-20-ANNHP9-4-20 N+T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

965 MPa140 ksi
1,100 MPa160 ksi

Yield Strength (0.2% offset)

760 MPa110 ksi
930 MPa135 ksi

Elongation at Break

20%
19%

Compressive Strength

1,250 MPa181 ksi
960 MPa139 ksi

Shear Strength

800 MPa116 ksi
670 MPa97.2 ksi

Fatigue Strength (Endurance Limit)

650 MPa94.3 ksi
550 MPa79.8 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
190 MPa·√m173 ksi·√in

Charpy V-Notch Impact (RT)

95 J70.1 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

280 HB
320 HB

Hardness, Rockwell C

29 HRC
34 HRC

Hardness, Vickers

410 HV
336 HV

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 62%

Physical

Density and transition temperatures.

Same in both: Density 7.83 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.

Thermal Conductivity

30 W/m·K17.3 BTU/hr·ft·°F
32 W/m·K18.5 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.8 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -100°C-148 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

5.5×10⁻⁷ Ω·m21.7 µΩ·in
5.4×10⁻⁷ Ω·m21.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 15 / 100

Manufacturability

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

Machinability

42 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
38%

Weldability

70 / 100
75 / 100

Formability (cold)

45 / 100
32 / 100

Same in both: Brazeability / Solderability 40 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 42 MJ/kg18,057 BTU/lb · Embodied Carbon (primary production) 3.4 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 20%

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 scaleHP9-4-20

HP9-4-20-ANN vs HP9-4-20 N+T — frequently asked

Is HP9-4-20 N+T stronger than HP9-4-20-ANN?

Yes. HP9-4-20 N+T has a typical yield strength of 930 MPa (135 ksi) against 760 MPa (110 ksi) for HP9-4-20-ANN — about 22% more. Tensile strength is 1,100 MPa (160 ksi) vs 965 MPa (140 ksi).

Which condition does FabDigit quote by default, ANN or N+T?

QT-190 is the default HP9-4-20 condition in the FabDigit quote flow (neither ANN nor N+T). 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, HP9-4-20-ANN or HP9-4-20 N+T?

HP9-4-20-ANN, by a small margin. Both rate fair for machinability — 42/100 against 35/100 for HP9-4-20 N+T; for welding the order is HP9-4-20 N+T first (very good, 75/100) then HP9-4-20-ANN (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in HP9-4-20-ANN and HP9-4-20 N+T 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.