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Steel 6118-A vs 6118-HR

Steel · 6118 temper comparison

6118-A and 6118-HR are two conditions of the same steel grade, 6118: A (solution annealed) versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 6118-HR is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 315 MPa (45.7 ksi) for 6118-A, about 11% more; tensile strength follows at 540 MPa (78.3 ksi) vs 470 MPa (68.2 ksi). In exchange, 6118-A is the more ductile: elongation 31% versus 24% for 6118-HR, and 6118-HR is harder (160 HB vs 137 HB).

6118-AChoose it when the part is bent, formed or impact-loaded.

6118-HRChoose it when strength drives the design.

6118-A vs 6118-HR: properties

6118-A6118-HR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

470 MPa68.2 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

315 MPa45.7 ksi
350 MPa50.8 ksi

Elongation at Break

31%
24%

Reduction in Area

66%
50%

Shear Strength

300 MPa43.5 ksi
350 MPa50.8 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

100 J73.8 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

137 HB
160 HB

Hardness, Rockwell B

76 HRB
84 HRB

Hardness, Vickers

145 HV
168 HV

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

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.

Same in both: Thermal Conductivity 45 W/m·K26 BTU/hr·ft·°F · 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 · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.5 % IACS · Electrical Resistivity 2.3×10⁻⁷ Ω·m9.06 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
11 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V

Manufacturability

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

Machinability

58 / 100
53 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Formability (cold)

60 / 100
55 / 100

Same in both: Weldability 65 / 100 · Brazeability / Solderability 70 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale6118

6118-A vs 6118-HR — frequently asked

Is 6118-HR stronger than 6118-A?

Yes. 6118-HR has a typical yield strength of 350 MPa (50.8 ksi) against 315 MPa (45.7 ksi) for 6118-A — about 11% more. Tensile strength is 540 MPa (78.3 ksi) vs 470 MPa (68.2 ksi).

Which condition does FabDigit quote by default, A or HR?

A is the default 6118 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, 6118-A or 6118-HR?

6118-A. Its machinability rates good (58/100) against fair (53/100) for 6118-HR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 6118-A and 6118-HR 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.