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Steel ZG270-500 Q&T vs ZG270-500-SR

Steel · ZG270-500 temper comparison

ZG270-500 Q&T and ZG270-500-SR are two conditions of the same steel grade, ZG270-500: Q&T (quenched and tempered) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. ZG270-500 Q&T is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 290 MPa (42.1 ksi) for ZG270-500-SR, about 45% more; tensile strength follows at 640 MPa (92.8 ksi) vs 530 MPa (76.9 ksi). In exchange, ZG270-500-SR is the more ductile: elongation 23% versus 18% for ZG270-500 Q&T, and ZG270-500 Q&T is harder (195 HB vs 158 HB). On the shop floor, ZG270-500-SR machines more easily (good vs fair).

ZG270-500 Q&TChoose it when strength drives the design.

ZG270-500-SRChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

ZG270-500 Q&T vs ZG270-500-SR: properties

ZG270-500 Q&TZG270-500-SR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

640 MPa92.8 ksi
530 MPa76.9 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
290 MPa42.1 ksi

Elongation at Break

18%
23%

Reduction in Area

40%
35%

Compressive Strength

300 MPa43.5 ksi
290 MPa42.1 ksi

Shear Strength

380 MPa55.1 ksi
370 MPa53.7 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
225 MPa32.6 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
78 MPa·√m71 ksi·√in

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

195 HB
158 HB

Hardness, Rockwell B

84 HRB
83 HRB

Hardness, Vickers

205 HV
166 HV

Same in both: Elastic (Young's) Modulus 202 GPa29.3 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.83 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Same in both: Thermal Conductivity 48 W/m·K27.7 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 425°C797 °F · Min Service Temperature -29°C-20 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 11 / 100

Manufacturability

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

Machinability

50 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
62%

Weldability

65 / 100
74 / 100

Formability (cold)

25 / 100
26 / 100

Same in both: Castability 68 / 100 · Brazeability / Solderability 60 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 50 L/kg6 gal/lb · Typical Recycled Content 85%

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 scaleZG270-500

ZG270-500 Q&T vs ZG270-500-SR — frequently asked

Is ZG270-500 Q&T stronger than ZG270-500-SR?

Yes. ZG270-500 Q&T has a typical yield strength of 420 MPa (60.9 ksi) against 290 MPa (42.1 ksi) for ZG270-500-SR — about 45% more. Tensile strength is 640 MPa (92.8 ksi) vs 530 MPa (76.9 ksi).

Which condition does FabDigit quote by default, Q&T or SR?

N is the default ZG270-500 condition in the FabDigit quote flow (neither Q&T nor SR). 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, ZG270-500 Q&T or ZG270-500-SR?

ZG270-500-SR. Its machinability rates good (60/100) against fair (50/100) for ZG270-500 Q&T; for welding the order is ZG270-500-SR first (very good, 74/100) then ZG270-500 Q&T (good, 65/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in ZG270-500 Q&T and ZG270-500-SR 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.