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Steel 45L-A vs 45L-F

Steel · 45L temper comparison

45L-A and 45L-F are two conditions of the same steel grade, 45L: A (solution annealed) versus F (as fabricated). The chemistry is identical, so every difference below comes from the condition. Both yield at about 290 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (solution annealed versus as fabricated). 45L-A is the more ductile: elongation 15% versus 8% for 45L-F, and 45L-F is harder (190 HB vs 179 HB). On the shop floor, 45L-A machines more easily (good vs fair) and 45L-A welds better (fair vs poor).

45L-AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

45L-A vs 45L-F: properties

45L-A45L-F

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

550 MPa79.8 ksi
540 MPa78.3 ksi

Elongation at Break

15%
8%

Reduction in Area

25%
14%

Shear Strength

330 MPa47.9 ksi
325 MPa47.1 ksi

Fatigue Strength (Endurance Limit)

225 MPa32.6 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
38 MPa·√m34.6 ksi·√in

Charpy V-Notch Impact (RT)

22 J16.2 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

179 HB
190 HB

Hardness, Rockwell B

88 HRB
91 HRB

Hardness, Vickers

188 HV
200 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 · Yield Strength (0.2% offset) 290 MPa42.1 ksi · Compressive Strength 290 MPa42.1 ksi

Physical

Density and transition temperatures.

Same in both: Density 7.83 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

49 W/m·K28.3 BTU/hr·ft·°F
47 W/m·K27.2 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
380°C716 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.7 % IACS
8.5 % IACS

Electrical Resistivity

1.98×10⁻⁷ Ω·m7.8 µΩ·in
2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

11 / 100
10 / 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

60 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
50%

Weldability

35 / 100
25 / 100

Formability (cold)

22 / 100
10 / 100

Same in both: Castability 70 / 100 · Brazeability / Solderability 55 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 35 L/kg4.2 gal/lb · Typical Recycled Content 80%

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 scale45L

45L-A vs 45L-F — frequently asked

What is the difference between 45L-A and 45L-F?

45L-A and 45L-F are two conditions of the same steel grade, 45L: A (solution annealed) versus F (as fabricated). The chemistry is identical, so every difference below comes from the condition. Both yield at about 290 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (solution annealed versus as fabricated).

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

N+T is the default 45L condition in the FabDigit quote flow (neither A nor F). 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, 45L-A or 45L-F?

45L-A. Its machinability rates good (60/100) against fair (50/100) for 45L-F; for welding the order is 45L-A first (fair, 35/100) then 45L-F (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 45L-A and 45L-F 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.