Steel 8637-HR vs 8637-IH
Steel · 8637 temper comparison
8637-HR and 8637-IH are two conditions of the same steel grade, 8637: HR (hot rolled) versus IH (induction hardened). The chemistry is identical, so every difference below comes from the condition. 8637-IH is the stronger of the two: yield strength 860 MPa (125 ksi) against 470 MPa (68.2 ksi) for 8637-HR, about 83% more; tensile strength follows at 965 MPa (140 ksi) vs 760 MPa (110 ksi). In exchange, 8637-HR is the more ductile: elongation 20% versus 15% for 8637-IH, and 8637-IH is harder (600 HB vs 217 HB). 8637-HR runs hotter in service (400°C vs 180°C continuous). On the shop floor, 8637-HR machines more easily (fair vs poor) and 8637-HR welds better (fair vs poor).
8637-HRChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
8637-IHChoose it when strength drives the design.
8637-HR vs 8637-IH: 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.
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 C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 45%
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 475 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 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 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: Brazeability / Solderability 55 / 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.
8637-HR vs 8637-IH — frequently asked
Is 8637-IH stronger than 8637-HR?
Yes. 8637-IH has a typical yield strength of 860 MPa (125 ksi) against 470 MPa (68.2 ksi) for 8637-HR — about 83% more. Tensile strength is 965 MPa (140 ksi) vs 760 MPa (110 ksi).
Which condition does FabDigit quote by default, HR or IH?
QT28-32HRC is the default 8637 condition in the FabDigit quote flow (neither HR nor IH). 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, 8637-HR or 8637-IH?
8637-HR. Its machinability rates fair (52/100) against poor (15/100) for 8637-IH; for welding the order is 8637-HR first (fair, 35/100) then 8637-IH (poor, 15/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 8637-HR and 8637-IH 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.