FabDigitFabDigit

Steel 1.2842 Annealed vs 1.2842-QT300

Steel · 1.2842 temper comparison

1.2842 Annealed and 1.2842-QT300 are two conditions of the same steel grade, 1.2842: Annealed versus QT300 (Q&T 300 °C). The chemistry is identical, so every difference below comes from the condition. 1.2842-QT300 is the stronger of the two: yield strength 1,620 MPa (235 ksi) against 420 MPa (60.9 ksi) for 1.2842 Annealed, about 3.9 times as much; tensile strength follows at 1,900 MPa (276 ksi) vs 700 MPa (102 ksi). In exchange, 1.2842 Annealed is the more ductile: elongation 16% versus 3% for 1.2842-QT300, and 1.2842-QT300 is harder (560 HB vs 215 HB). 1.2842 Annealed runs hotter in service (400°C vs 250°C continuous). On the shop floor, 1.2842 Annealed machines more easily (fair vs not recommended) and 1.2842 Annealed welds better (poor vs not recommended).

1.2842 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1.2842-QT300Choose it when strength drives the design.

1.2842 Annealed vs 1.2842-QT300: properties

1.2842 Annealed1.2842-QT300

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
208 GPa30.2 Msi

Tensile Strength (Ultimate)

700 MPa102 ksi
1,900 MPa276 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
1,620 MPa235 ksi

Elongation at Break

16%
3%

Reduction in Area

35%
7%

Compressive Strength

450 MPa65.3 ksi
2,200 MPa319 ksi

Shear Strength

430 MPa62.4 ksi
1,150 MPa167 ksi

Fatigue Strength (Endurance Limit)

320 MPa46.4 ksi
580 MPa84.1 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
24 MPa·√m21.8 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

215 HB
560 HB

Hardness, Rockwell C

17 HRC
55 HRC

Hardness, Vickers

225 HV
595 HV

Same in both: Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 95 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,470°C2,678 °F

Thermal

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

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
32 W/m·K18.5 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7 % IACS
6.5 % IACS

Electrical Resistivity

2.5×10⁻⁷ Ω·m9.84 µΩ·in
2.7×10⁻⁷ Ω·m10.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
11 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

45 / 100
12 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
12%

Weldability

20 / 100
5 / 100

Formability (cold)

30 / 100
5 / 100

Same in both: Castability 20 / 100 · Brazeability / Solderability 40 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 65 L/kg7.8 gal/lb · Typical Recycled Content 35%

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 scale1.2842

1.2842 Annealed vs 1.2842-QT300 — frequently asked

Is 1.2842-QT300 stronger than 1.2842 Annealed?

Yes. 1.2842-QT300 has a typical yield strength of 1,620 MPa (235 ksi) against 420 MPa (60.9 ksi) for 1.2842 Annealed — about 3.9 times as much. Tensile strength is 1,900 MPa (276 ksi) vs 700 MPa (102 ksi).

Which condition does FabDigit quote by default, Annealed or QT300?

Annealed is the default 1.2842 condition in the FabDigit quote flow. 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, 1.2842 Annealed or 1.2842-QT300?

1.2842 Annealed. Its machinability rates fair (45/100) against not recommended (12/100) for 1.2842-QT300; for welding the order is 1.2842 Annealed first (poor, 20/100) then 1.2842-QT300 (not recommended, 5/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.2842 Annealed and 1.2842-QT300 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.