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Steel 1552 QT-28-32HRC vs 1552 QT-38-42HRC

Steel · 1552 temper comparison

1552 QT-28-32HRC and 1552 QT-38-42HRC are two conditions of the same steel grade, 1552: QT-28-32HRC versus QT-38-42HRC. The chemistry is identical, so every difference below comes from the condition. 1552 QT-38-42HRC is the stronger of the two: yield strength 1,105 MPa (160 ksi) against 800 MPa (116 ksi) for 1552 QT-28-32HRC, about 38% more; tensile strength follows at 1,275 MPa (185 ksi) vs 965 MPa (140 ksi). In exchange, 1552 QT-28-32HRC is the more ductile: elongation 16% versus 11% for 1552 QT-38-42HRC, and 1552 QT-38-42HRC is harder (375 HB vs 293 HB). 1552 QT-28-32HRC runs hotter in service (425°C vs 350°C continuous). On the shop floor, 1552 QT-28-32HRC machines more easily (fair vs poor).

1552 QT-28-32HRCChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1552 QT-38-42HRCChoose it when strength drives the design.

1552 QT-28-32HRC vs 1552 QT-38-42HRC: properties

1552 QT-28-32HRC1552 QT-38-42HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

965 MPa140 ksi
1,275 MPa185 ksi

Yield Strength (0.2% offset)

800 MPa116 ksi
1,105 MPa160 ksi

Elongation at Break

16%
11%

Reduction in Area

48%
38%

Shear Strength

580 MPa84.1 ksi
435 MPa63.1 ksi

Fatigue Strength (Endurance Limit)

440 MPa63.8 ksi
540 MPa78.3 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

35 J25.8 ft·lbf
18 J13.3 ft·lbf

Hardness, Brinell

293 HB
375 HB

Hardness, Vickers

307 HV
392 HV

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 415 MPa60.2 ksi · Hardness, Rockwell B 95 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Max Service Temperature (continuous)

425°C797 °F
350°C662 °F

Same in both: Thermal Conductivity 49 W/m·K28.3 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 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

42 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
32%

Weldability

20 / 100
12 / 100

Same in both: Formability (cold) 30 / 100 · Brazeability / Solderability 55 / 100 · Polishability 55 / 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 40 L/kg4.8 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 scale1552

1552 QT-28-32HRC vs 1552 QT-38-42HRC — frequently asked

Is 1552 QT-38-42HRC stronger than 1552 QT-28-32HRC?

Yes. 1552 QT-38-42HRC has a typical yield strength of 1,105 MPa (160 ksi) against 800 MPa (116 ksi) for 1552 QT-28-32HRC — about 38% more. Tensile strength is 1,275 MPa (185 ksi) vs 965 MPa (140 ksi).

Which condition does FabDigit quote by default, QT-28-32HRC or QT-38-42HRC?

HR is the default 1552 condition in the FabDigit quote flow (neither QT-28-32HRC nor QT-38-42HRC). 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, 1552 QT-28-32HRC or 1552 QT-38-42HRC?

1552 QT-28-32HRC. Its machinability rates fair (42/100) against poor (30/100) for 1552 QT-38-42HRC; for welding the order is 1552 QT-28-32HRC first (poor, 20/100) then 1552 QT-38-42HRC (not recommended, 12/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1552 QT-28-32HRC and 1552 QT-38-42HRC 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.