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Steel SM570-AR vs SM570-QT

Steel · SM570 temper comparison

SM570-AR and SM570-QT are two conditions of the same steel grade, SM570: AR (as-rolled) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. SM570-QT is the stronger of the two: yield strength 530 MPa (76.9 ksi) against 500 MPa (72.5 ksi) for SM570-AR, about 6% more.

SM570-QTChoose it when strength drives the design.

SM570-AR vs SM570-QT: properties

SM570-ARSM570-QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

640 MPa92.8 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

500 MPa72.5 ksi
530 MPa76.9 ksi

Elongation at Break

21%
23%

Reduction in Area

50%
55%

Compressive Strength

500 MPa72.5 ksi
490 MPa71.1 ksi

Shear Strength

395 MPa57.3 ksi
390 MPa56.6 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
145 MPa·√m132 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
130 J95.9 ft·lbf

Hardness, Brinell

195 HB
205 HB

Hardness, Rockwell B

93 HRB
95 HRB

Hardness, Vickers

205 HV
200 HV

Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 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) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 8.6 % IACS · Electrical Resistivity 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 12 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

55%
50%

Weldability

70 / 100
68 / 100

Formability (cold)

50 / 100
48 / 100

Same in both: Machinability 52 / 100 · Brazeability / Solderability 55 / 100 · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 27 MJ/kg11,608 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

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 scaleSM570

SM570-AR vs SM570-QT — frequently asked

Is SM570-QT stronger than SM570-AR?

Yes. SM570-QT has a typical yield strength of 530 MPa (76.9 ksi) against 500 MPa (72.5 ksi) for SM570-AR — about 6% more. Tensile strength is 660 MPa (95.7 ksi) vs 640 MPa (92.8 ksi).

Which condition does FabDigit quote by default, AR or QT?

N is the default SM570 condition in the FabDigit quote flow (neither AR nor QT). 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.

When should I choose SM570-AR over SM570-QT?

Pick SM570-QT when strength drives the design.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SM570-AR and SM570-QT 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.