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Steel 1151-IH vs 1151-N

Steel · 1151 temper comparison

1151-IH and 1151-N are two conditions of the same steel grade, 1151: IH (induction hardened) versus N (normalized). 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 415 MPa (60.2 ksi) for 1151-N, about 54% more. In exchange, 1151-N is the more ductile: elongation 18% versus 8% for 1151-IH, and 1151-IH is harder (615 HB vs 207 HB). 1151-N runs hotter in service (400°C vs 200°C continuous) and 1151-N conducts electricity better (9.8 % IACS vs 8.5 % IACS). On the shop floor, 1151-N machines more easily (very good vs poor) and 1151-N welds better (poor vs not recommended).

1151-IHChoose it when strength drives the design.

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

1151-IH vs 1151-N: properties

1151-IH1151-N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

745 MPa108 ksi
720 MPa104 ksi

Yield Strength (0.2% offset)

640 MPa92.8 ksi
415 MPa60.2 ksi

Elongation at Break

8%
18%

Reduction in Area

22%
38%

Compressive Strength

1,800 MPa261 ksi
420 MPa60.9 ksi

Shear Strength

480 MPa69.6 ksi
440 MPa63.8 ksi

Fatigue Strength (Endurance Limit)

450 MPa65.3 ksi
320 MPa46.4 ksi

Fracture Toughness (K_IC)

30 MPa·√m27.3 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

10 J7.4 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

615 HB
207 HB

Hardness, Rockwell B

96 HRB
94 HRB

Hardness, Vickers

650 HV
218 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

45 W/m·K26 BTU/hr·ft·°F
49.5 W/m·K28.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
400°C752 °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

8.5 % IACS
9.8 % IACS

Electrical Resistivity

2×10⁻⁷ Ω·m7.87 µΩ·in
1.76×10⁻⁷ Ω·m6.93 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

20 / 100
71 / 100

Machinability Rating (AISI 1212 = 100 %)

15%
68%

Weldability

5 / 100
22 / 100

Formability (cold)

5 / 100
35 / 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-IH vs 1151-N — frequently asked

Is 1151-IH stronger than 1151-N?

Yes. 1151-IH has a typical yield strength of 640 MPa (92.8 ksi) against 415 MPa (60.2 ksi) for 1151-N — about 54% more. Tensile strength is 745 MPa (108 ksi) vs 720 MPa (104 ksi).

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

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

1151-N. Its machinability rates very good (71/100) against poor (20/100) for 1151-IH; for welding the order is 1151-N first (poor, 22/100) then 1151-IH (not recommended, 5/100).

Ready to make it?

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