Steel Cr12 Annealed vs Cr12 Q&T 55-58 HRC
Steel · Cr12 temper comparison
Cr12 Annealed and Cr12 Q&T 55-58 HRC are two conditions of the same steel grade, Cr12: Annealed versus Q&T 55-58 HRC (tempered 350–400 °C for higher toughness). The chemistry is identical, so every difference below comes from the condition. Cr12 Q&T 55-58 HRC is the stronger of the two: yield strength 1,550 MPa (225 ksi) against 480 MPa (69.6 ksi) for Cr12 Annealed, about 3.2 times as much; tensile strength follows at 1,800 MPa (261 ksi) vs 820 MPa (119 ksi). In exchange, Cr12 Annealed is the more ductile: elongation 12% versus 2% for Cr12 Q&T 55-58 HRC, and Cr12 Q&T 55-58 HRC is harder (57 HRC vs 22 HRC). Cr12 Q&T 55-58 HRC runs hotter in service (300°C vs 200°C continuous). On the shop floor, Cr12 Annealed machines more easily (poor vs not recommended).
Cr12 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
Cr12 Q&T 55-58 HRCChoose it when strength drives the design, or when the part sees heat.
Cr12 Annealed vs Cr12 Q&T 55-58 HRC: 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.
Cr12 AnnealedCr12 Q&T 55-58 HRC
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Charpy V-Notch Impact (RT)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Hardness, Brinell 240 HB
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °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 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 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
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
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 25 / 100 · Brazeability / Solderability 35 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 36 MJ/kg15,477 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 45%
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.
Cr12 Annealed vs Cr12 Q&T 55-58 HRC — frequently asked
Is Cr12 Q&T 55-58 HRC stronger than Cr12 Annealed?
Yes. Cr12 Q&T 55-58 HRC has a typical yield strength of 1,550 MPa (225 ksi) against 480 MPa (69.6 ksi) for Cr12 Annealed — about 3.2 times as much. Tensile strength is 1,800 MPa (261 ksi) vs 820 MPa (119 ksi).
Which condition does FabDigit quote by default, Annealed or Q&T 55-58 HRC?
Annealed is the default Cr12 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, Cr12 Annealed or Cr12 Q&T 55-58 HRC?
Cr12 Annealed. Its machinability rates poor (32/100) against not recommended (10/100) for Cr12 Q&T 55-58 HRC; for welding the order is Cr12 Annealed first (not recommended, 12/100) then Cr12 Q&T 55-58 HRC (not recommended, 5/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Cr12 Annealed and Cr12 Q&T 55-58 HRC 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.