Steel A842 Grade 450-IH vs A842 Grade 450-SR
Steel · A842 Grade 450 temper comparison
A842 Grade 450-IH and A842 Grade 450-SR are two conditions of the same steel grade, A842 Grade 450: IH (induction hardened) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 350 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (induction hardened versus stress relieved). A842 Grade 450-SR is the more ductile: elongation 1.8% versus 1.2% for A842 Grade 450-IH, and A842 Grade 450-IH is harder (52 HRC vs 20 HRC). A842 Grade 450-SR runs hotter in service (400°C vs 250°C continuous). On the shop floor, A842 Grade 450-SR machines more easily (fair vs not recommended) and A842 Grade 450-SR welds better (poor vs not recommended).
A842 Grade 450-SRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
A842 Grade 450-IH vs A842 Grade 450-SR: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
A842 Grade 450-IHA842 Grade 450-SR
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 150 GPa21.8 Msi · 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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 36 W/m·K20.8 BTU/hr·ft·°F · 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 · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
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.
A842 Grade 450-IH vs A842 Grade 450-SR — frequently asked
What is the difference between A842 Grade 450-IH and A842 Grade 450-SR?
A842 Grade 450-IH and A842 Grade 450-SR are two conditions of the same steel grade, A842 Grade 450: IH (induction hardened) versus SR (stress relieved). The chemistry is identical, so every difference below comes from the condition. Both yield at about 350 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (induction hardened versus stress relieved).
Which condition does FabDigit quote by default, IH or SR?
AS-CAST is the default A842 Grade 450 condition in the FabDigit quote flow (neither IH 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-IH or A842 Grade 450-SR?
A842 Grade 450-SR. Its machinability rates fair (38/100) against not recommended (12/100) for A842 Grade 450-IH; for welding the order is A842 Grade 450-SR first (poor, 30/100) then A842 Grade 450-IH (not recommended, 10/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in A842 Grade 450-IH 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.