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Steel 1151-ANN vs 1151-IH

Steel · 1151 temper comparison

1151-ANN and 1151-IH are two conditions of the same steel grade, 1151: ANN (annealed) versus IH (induction hardened). The chemistry is identical, so every difference below comes from the condition. 1151-IH is the stronger of the two: yield strength 640 MPa (92.8 ksi) against 320 MPa (46.4 ksi) for 1151-ANN, about 100% more; tensile strength follows at 745 MPa (108 ksi) vs 585 MPa (84.8 ksi). In exchange, 1151-ANN is the more ductile: elongation 22% versus 8% for 1151-IH, and 1151-IH is harder (615 HB vs 167 HB). 1151-ANN runs hotter in service (400°C vs 200°C continuous) and 1151-ANN conducts heat better (51 W/m·K vs 45 W/m·K). On the shop floor, 1151-ANN machines more easily (good vs poor) and 1151-ANN welds better (poor vs not recommended).

1151-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1151-IHChoose it when strength drives the design.

1151-ANN vs 1151-IH: properties

1151-ANN1151-IH

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

585 MPa84.8 ksi
745 MPa108 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
640 MPa92.8 ksi

Elongation at Break

22%
8%

Reduction in Area

45%
22%

Compressive Strength

325 MPa47.1 ksi
1,800 MPa261 ksi

Shear Strength

360 MPa52.2 ksi
480 MPa69.6 ksi

Fatigue Strength (Endurance Limit)

265 MPa38.4 ksi
450 MPa65.3 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
30 MPa·√m27.3 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
10 J7.4 ft·lbf

Hardness, Brinell

167 HB
615 HB

Hardness, Rockwell B

85 HRB
96 HRB

Hardness, Vickers

175 HV
650 HV

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 140 GPa20.3 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 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

51 W/m·K29.5 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.7 µm/m·K6.5 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
8.5 % IACS

Electrical Resistivity

1.72×10⁻⁷ Ω·m6.77 µΩ·in
2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.65 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

68 / 100
20 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
15%

Weldability

25 / 100
5 / 100

Formability (cold)

50 / 100
5 / 100

Same in both: Castability 40 / 100 · Brazeability / Solderability 55 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 50 L/kg6 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 scale1151

1151-ANN vs 1151-IH — frequently asked

Is 1151-IH stronger than 1151-ANN?

Yes. 1151-IH has a typical yield strength of 640 MPa (92.8 ksi) against 320 MPa (46.4 ksi) for 1151-ANN — about 100% more. Tensile strength is 745 MPa (108 ksi) vs 585 MPa (84.8 ksi).

Which condition does FabDigit quote by default, ANN or IH?

CD is the default 1151 condition in the FabDigit quote flow (neither ANN nor IH). 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, 1151-ANN or 1151-IH?

1151-ANN. Its machinability rates good (68/100) against poor (20/100) for 1151-IH; for welding the order is 1151-ANN first (poor, 25/100) then 1151-IH (not recommended, 5/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1151-ANN and 1151-IH 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.