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Steel A842 Grade 450-N vs A842 Grade 450-SR

Steel · A842 Grade 450 temper comparison

A842 Grade 450-N and A842 Grade 450-SR are two conditions of the same steel grade, A842 Grade 450: N (normalized) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. A842 Grade 450-N is the stronger of the two: yield strength 390 MPa (56.6 ksi) against 340 MPa (49.3 ksi) for A842 Grade 450-SR, about 15% more; tensile strength follows at 530 MPa (76.9 ksi) vs 470 MPa (68.2 ksi). In exchange, A842 Grade 450-SR is the more ductile: elongation 1.8% versus 1.2% for A842 Grade 450-N, and A842 Grade 450-N is harder (260 HB vs 230 HB). On the shop floor, A842 Grade 450-SR welds better (30 vs 20 out of 100).

A842 Grade 450-NChoose it when strength drives the design.

A842 Grade 450-SRChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

A842 Grade 450-N vs A842 Grade 450-SR: properties

A842 Grade 450-NA842 Grade 450-SR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

155 GPa22.5 Msi
150 GPa21.8 Msi

Tensile Strength (Ultimate)

530 MPa76.9 ksi
470 MPa68.2 ksi

Yield Strength (0.2% offset)

390 MPa56.6 ksi
340 MPa49.3 ksi

Elongation at Break

1.2%
1.8%

Compressive Strength

1,020 MPa148 ksi
920 MPa133 ksi

Shear Strength

460 MPa66.7 ksi
415 MPa60.2 ksi

Fatigue Strength (Endurance Limit)

220 MPa31.9 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

23 MPa·√m20.9 ksi·√in
26 MPa·√m23.7 ksi·√in

Charpy V-Notch Impact (RT)

2 J1.5 ft·lbf
3 J2.2 ft·lbf

Hardness, Brinell

260 HB
230 HB

Hardness, Rockwell B

99 HRB
98 HRB

Hardness, Rockwell C

25 HRC
20 HRC

Hardness, Vickers

272 HV
240 HV

Same in both: Shear Modulus 60 GPa8.7 Msi · Bulk Modulus 105 GPa15.2 Msi · Poisson's Ratio 0.26

Physical

Density and transition temperatures.

Same in both: Density 7.15 g/cm³0.26 lb/in³ · Melting Point (Solidus) 1,150°C2,102 °F · Liquidus Temperature 1,175°C2,147 °F

Thermal

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

Thermal Conductivity

34 W/m·K19.6 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 465 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 220 J/g94.6 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.1 % IACS
2.2 % IACS

Electrical Resistivity

8.2×10⁻⁷ Ω·m32.3 µΩ·in
8×10⁻⁷ Ω·m31.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 16 / 100

Manufacturability

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

Machinability

30 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
48%

Weldability

20 / 100
30 / 100

Formability (cold)

2 / 100
3 / 100

Same in both: Castability 62 / 100 · Brazeability / Solderability 40 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 22 MJ/kg9,458 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 30 L/kg3.6 gal/lb · Typical Recycled Content 90%

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 scaleA842 Grade 450

A842 Grade 450-N vs A842 Grade 450-SR — frequently asked

Is A842 Grade 450-N stronger than A842 Grade 450-SR?

Yes. A842 Grade 450-N has a typical yield strength of 390 MPa (56.6 ksi) against 340 MPa (49.3 ksi) for A842 Grade 450-SR — about 15% more. Tensile strength is 530 MPa (76.9 ksi) vs 470 MPa (68.2 ksi).

Which condition does FabDigit quote by default, N or SR?

AS-CAST is the default A842 Grade 450 condition in the FabDigit quote flow (neither N 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, A842 Grade 450-N or A842 Grade 450-SR?

A842 Grade 450-SR. Its machinability rates fair (38/100) against poor (30/100) for A842 Grade 450-N; for welding the order is A842 Grade 450-SR first (poor, 30/100) then A842 Grade 450-N (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A842 Grade 450-N and A842 Grade 450-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.