Stainless Steel 1.3549 +C vs 1.3549 QT 55-58 HRC
Stainless Steel · 1.3549 temper comparison
1.3549 +C and 1.3549 QT 55-58 HRC are two conditions of the same stainless steel grade, 1.3549: +C (cold drawn) versus QT 55-58 HRC (hardened 1020–1060 °C + tempered ~250 °C). The chemistry is identical, so every difference below comes from the condition. 1.3549 QT 55-58 HRC is the stronger of the two: yield strength 1,750 MPa (254 ksi) against 620 MPa (89.9 ksi) for 1.3549 +C, about 182% more; tensile strength follows at 1,900 MPa (276 ksi) vs 880 MPa (128 ksi). In exchange, 1.3549 +C is the more ductile: elongation 9% versus 3% for 1.3549 QT 55-58 HRC, and 1.3549 +C is harder (275 HB vs 245 HB). 1.3549 +C runs hotter in service (250°C vs 200°C continuous). On the shop floor, 1.3549 +C machines more easily (poor vs not recommended).
1.3549 +CChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
1.3549 QT 55-58 HRCChoose it when strength drives the design.
1.3549 +C vs 1.3549 QT 55-58 HRC: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
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: Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Hardness, Rockwell B 99 HRB
Physical
Density and transition temperatures.
Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,420°C2,588 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 24 W/m·K13.9 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.4 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -70°C-94 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Polishability
Same in both: Weldability 10 / 100 · Brazeability / Solderability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 4.7 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb · Typical Recycled Content 40%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
1.3549 +C vs 1.3549 QT 55-58 HRC — frequently asked
Is 1.3549 QT 55-58 HRC stronger than 1.3549 +C?
Yes. 1.3549 QT 55-58 HRC has a typical yield strength of 1,750 MPa (254 ksi) against 620 MPa (89.9 ksi) for 1.3549 +C — about 182% more. Tensile strength is 1,900 MPa (276 ksi) vs 880 MPa (128 ksi).
Which condition does FabDigit quote by default, +C or QT 55-58 HRC?
A is the default 1.3549 condition in the FabDigit quote flow (neither +C nor QT 55-58 HRC). 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, 1.3549 +C or 1.3549 QT 55-58 HRC?
1.3549 +C. Its machinability rates poor (32/100) against not recommended (8/100) for 1.3549 QT 55-58 HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.3549 +C and 1.3549 QT 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.