FabDigitFabDigit

Steel 38CrMoAlA Annealed vs 38CrMoAlA-HR

Steel · 38CrMoAlA temper comparison

38CrMoAlA Annealed and 38CrMoAlA-HR are two conditions of the same steel grade, 38CrMoAlA: Annealed versus HR (hot rolled). The chemistry is identical, so every difference below comes from the condition. 38CrMoAlA-HR is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 450 MPa (65.3 ksi) for 38CrMoAlA Annealed, about 22% more; tensile strength follows at 850 MPa (123 ksi) vs 720 MPa (104 ksi). In exchange, 38CrMoAlA Annealed is the more ductile: elongation 20% versus 16% for 38CrMoAlA-HR, and 38CrMoAlA-HR is harder (255 HB vs 210 HB). 38CrMoAlA Annealed runs hotter in service (500°C vs 450°C continuous). On the shop floor, 38CrMoAlA Annealed machines more easily (good vs fair).

38CrMoAlA AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

38CrMoAlA-HRChoose it when strength drives the design.

38CrMoAlA Annealed vs 38CrMoAlA-HR: properties

38CrMoAlA Annealed38CrMoAlA-HR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

720 MPa104 ksi
850 MPa123 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
550 MPa79.8 ksi

Elongation at Break

20%
16%

Reduction in Area

55%
45%

Compressive Strength

900 MPa131 ksi
570 MPa82.7 ksi

Shear Strength

640 MPa92.8 ksi
510 MPa74 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
385 MPa55.8 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
60 MPa·√m54.6 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
38 J28 ft·lbf

Hardness, Brinell

210 HB
255 HB

Hardness, Rockwell C

32 HRC
25 HRC

Hardness, Vickers

325 HV
268 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 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 7.8 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

33 W/m·K19.1 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Max Service Temperature (continuous)

500°C932 °F
450°C842 °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 -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
8.2 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.1×10⁻⁷ Ω·m8.27 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

55 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
50%

Weldability

25 / 100
22 / 100

Formability (cold)

40 / 100
30 / 100

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) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 55 L/kg6.6 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 scale38CrMoAlA

38CrMoAlA Annealed vs 38CrMoAlA-HR — frequently asked

Is 38CrMoAlA-HR stronger than 38CrMoAlA Annealed?

Yes. 38CrMoAlA-HR has a typical yield strength of 550 MPa (79.8 ksi) against 450 MPa (65.3 ksi) for 38CrMoAlA Annealed — about 22% more. Tensile strength is 850 MPa (123 ksi) vs 720 MPa (104 ksi).

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

Q&T is the default 38CrMoAlA condition in the FabDigit quote flow (neither Annealed nor HR). 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, 38CrMoAlA Annealed or 38CrMoAlA-HR?

38CrMoAlA Annealed. Its machinability rates good (55/100) against fair (42/100) for 38CrMoAlA-HR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 38CrMoAlA Annealed and 38CrMoAlA-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.