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Steel L6-A vs L6 Q&T 58-62 HRC

Steel · L6 temper comparison

L6-A and L6 Q&T 58-62 HRC are two conditions of the same steel grade, L6: A (solution annealed) versus Q&T 58-62 HRC (oil quenched, low temper ~175–205 °C). The chemistry is identical, so every difference below comes from the condition. L6 Q&T 58-62 HRC is the stronger of the two: yield strength 1,900 MPa (276 ksi) against 420 MPa (60.9 ksi) for L6-A, about 4.5 times as much; tensile strength follows at 2,250 MPa (326 ksi) vs 730 MPa (106 ksi). In exchange, L6-A is the more ductile: elongation 22% versus 1.5% for L6 Q&T 58-62 HRC, and L6 Q&T 58-62 HRC is harder (700 HV vs 207 HV). L6-A runs hotter in service (400°C vs 175°C continuous). On the shop floor, L6-A machines more easily (good vs not recommended) and L6-A welds better (poor vs not recommended).

L6-AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

L6 Q&T 58-62 HRCChoose it when strength drives the design.

L6-A vs L6 Q&T 58-62 HRC: properties

L6-AL6 Q&T 58-62 HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

730 MPa106 ksi
2,250 MPa326 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
1,900 MPa276 ksi

Elongation at Break

22%
1.5%

Reduction in Area

45%
5%

Compressive Strength

430 MPa62.4 ksi
2,500 MPa363 ksi

Shear Strength

440 MPa63.8 ksi
1,400 MPa203 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
800 MPa116 ksi

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
9 J6.6 ft·lbf

Hardness, Vickers

207 HV
700 HV

Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 197 HB · Hardness, Rockwell B 92 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.87 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

How each material carries heat and how hot it can run.

Max Service Temperature (continuous)

400°C752 °F
175°C347 °F

Same in both: Thermal Conductivity 38 W/m·K22 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 11 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

55 / 100
5 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
5%

Weldability

20 / 100
3 / 100

Formability (cold)

30 / 100
1 / 100

Polishability

65 / 100
72 / 100

Same in both: Castability 30 / 100 · Brazeability / Solderability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 33 MJ/kg14,187 BTU/lb · Embodied Carbon (primary production) 2.4 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleL6

L6-A vs L6 Q&T 58-62 HRC — frequently asked

Is L6 Q&T 58-62 HRC stronger than L6-A?

Yes. L6 Q&T 58-62 HRC has a typical yield strength of 1,900 MPa (276 ksi) against 420 MPa (60.9 ksi) for L6-A — about 4.5 times as much. Tensile strength is 2,250 MPa (326 ksi) vs 730 MPa (106 ksi).

Which condition does FabDigit quote by default, A or Q&T 58-62 HRC?

A is the default L6 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, L6-A or L6 Q&T 58-62 HRC?

L6-A. Its machinability rates good (55/100) against not recommended (5/100) for L6 Q&T 58-62 HRC; for welding the order is L6-A first (poor, 20/100) then L6 Q&T 58-62 HRC (not recommended, 3/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in L6-A and L6 Q&T 58-62 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.