Steel 5135-IH vs 5135-QT205
Steel · 5135 temper comparison
5135-IH and 5135-QT205 are two conditions of the same steel grade, 5135: IH (induction hardened) versus QT205 (Q&T 205 °C). The chemistry is identical, so every difference below comes from the condition. 5135-QT205 is the stronger of the two: yield strength 1,450 MPa (210 ksi) against 830 MPa (120 ksi) for 5135-IH, about 75% more; tensile strength follows at 1,660 MPa (241 ksi) vs 1,010 MPa (146 ksi). In exchange, 5135-IH is the more ductile: elongation 15% versus 10% for 5135-QT205, and 5135-IH is harder (570 HB vs 470 HB). 5135-IH runs hotter in service (200°C vs 150°C continuous).
5135-IHChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
5135-QT205Choose it when strength drives the design.
5135-IH vs 5135-QT205: 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
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
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 · Hardness, Rockwell B 85 HRB
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 1,490°C2,714 °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 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 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) -0.6 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 60 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 27 MJ/kg11,608 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%
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.
5135-IH vs 5135-QT205 — frequently asked
Is 5135-QT205 stronger than 5135-IH?
Yes. 5135-QT205 has a typical yield strength of 1,450 MPa (210 ksi) against 830 MPa (120 ksi) for 5135-IH — about 75% more. Tensile strength is 1,660 MPa (241 ksi) vs 1,010 MPa (146 ksi).
Which condition does FabDigit quote by default, IH or QT205?
A is the default 5135 condition in the FabDigit quote flow (neither IH nor QT205). 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, 5135-IH or 5135-QT205?
5135-QT205. Its machinability rates poor (20/100) against not recommended (12/100) for 5135-IH; for welding the order is 5135-QT205 first (poor, 20/100) then 5135-IH (not recommended, 12/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 5135-IH and 5135-QT205 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.