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Steel 1139-HR vs 1139 QT-22-26HRC

Steel · 1139 temper comparison

1139-HR and 1139 QT-22-26HRC are two conditions of the same steel grade, 1139: HR (hot rolled) versus QT-22-26HRC. The chemistry is identical, so every difference below comes from the condition. 1139 QT-22-26HRC is the stronger of the two: yield strength 660 MPa (95.7 ksi) against 345 MPa (50 ksi) for 1139-HR, about 91% more; tensile strength follows at 830 MPa (120 ksi) vs 620 MPa (89.9 ksi). 1139 QT-22-26HRC is harder — 248 HB against 179 HB for 1139-HR — which matters for wear surfaces and threads. On the shop floor, 1139-HR forms better (fair vs poor).

1139 QT-22-26HRCChoose it when strength drives the design, or when surface hardness matters.

1139-HR vs 1139 QT-22-26HRC: properties

1139-HR1139 QT-22-26HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
830 MPa120 ksi

Yield Strength (0.2% offset)

345 MPa50 ksi
660 MPa95.7 ksi

Elongation at Break

16%
17%

Reduction in Area

40%
50%

Shear Strength

375 MPa54.4 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
360 MPa52.2 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

179 HB
248 HB

Hardness, Rockwell B

89 HRB
100 HRB

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 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
425°C797 °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
9.5 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
1.8×10⁻⁷ Ω·m7.09 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

68 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

66%
62%

Weldability

30 / 100
25 / 100

Formability (cold)

40 / 100
20 / 100

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

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 45 L/kg5.4 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 scale1139

1139-HR vs 1139 QT-22-26HRC — frequently asked

Is 1139 QT-22-26HRC stronger than 1139-HR?

Yes. 1139 QT-22-26HRC has a typical yield strength of 660 MPa (95.7 ksi) against 345 MPa (50 ksi) for 1139-HR — about 91% more. Tensile strength is 830 MPa (120 ksi) vs 620 MPa (89.9 ksi).

Which condition does FabDigit quote by default, HR or QT-22-26HRC?

CD is the default 1139 condition in the FabDigit quote flow (neither HR nor QT-22-26HRC). 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, 1139-HR or 1139 QT-22-26HRC?

1139-HR, by a small margin. Both rate good for machinability — 68/100 against 60/100 for 1139 QT-22-26HRC; for welding the order is 1139-HR first (poor, 30/100) then 1139 QT-22-26HRC (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1139-HR and 1139 QT-22-26HRC 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.