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Steel 20Mn5 vs A285

Steel · grade comparison

Steel 20Mn5 and A285 are both steel grades. 20Mn5 is the stronger of the two: yield strength 320 MPa (46.4 ksi) against 250 MPa (36.3 ksi) for A285, about 28% more; tensile strength follows at 530 MPa (76.9 ksi) vs 450 MPa (65.3 ksi). In exchange, A285 is the more ductile: elongation 30% versus 25% for 20Mn5, and 20Mn5 is harder (155 HB vs 130 HB). A285 conducts electricity better (10.8 % IACS vs 9 % IACS). On the shop floor, A285 welds better (excellent vs very good) and 20Mn5 sits in a lower cost tier (budget, $) than A285 (standard, $$).

20Mn5Choose it when strength drives the design, or when cost is the deciding factor.

A285Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

20Mn5 vs A285: properties

20Mn5A285

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
200 GPa29 Msi

Shear Modulus

81 GPa11.7 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

530 MPa76.9 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
250 MPa36.3 ksi

Elongation at Break

25%
30%

Compressive Strength

320 MPa46.4 ksi
250 MPa36.3 ksi

Shear Strength

330 MPa47.9 ksi
290 MPa42.1 ksi

Fatigue Strength (Endurance Limit)

245 MPa35.5 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

155 HB
130 HB

Hardness, Rockwell B

82 HRB
72 HRB

Hardness, Vickers

163 HV
—

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 55%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,460°C2,660 °F

Liquidus Temperature

1,500°C2,732 °F
1,515°C2,759 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

48 W/m·K27.7 BTU/hr·ft·°F
51 W/m·K29.5 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

12.2 µm/m·K6.8 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

270 J/g116 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Min Service Temperature

-46°C-51 °F
-29°C-20 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
10.8 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 µΩ·in
1.6×10⁻⁷ Ω·m6.3 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) -0.62 V

Manufacturability

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

Machinability

60 / 100
68 / 100

Weldability

78 / 100
92 / 100

Formability (cold)

60 / 100
82 / 100

Brazeability / Solderability

65 / 100
60 / 100

Polishability

45 / 100
40 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 65%

Sustainability

Primary-production footprint per kilogram.

Embodied Water

45 L/kg5.4 gal/lb
30 L/kg3.6 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

68 kN·m/kg
57 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
25.5 MN·m/kg

Modulus of Resilience

244 kJ/m³
156 kJ/m³

Thermal Diffusivity

13 mm²/s
13.8 mm²/s

Same in both: Thermal Shock Resistance Index 10

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 scaleA28520Mn5

Manufacturing and finishing

Capability20Mn5A285
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

20Mn5 vs A285 — frequently asked

Is 20Mn5 stronger than A285?

Yes. 20Mn5 has a typical yield strength of 320 MPa (46.4 ksi) against 250 MPa (36.3 ksi) for A285 — about 28% more. Tensile strength is 530 MPa (76.9 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 20Mn5 or A285?

20Mn5 is the lower-cost material: it sits in the budget tier ($) while A285 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 20Mn5 or A285?

A285, by a small margin. Both rate good for machinability — 68/100 against 60/100 for 20Mn5; for welding the order is A285 first (excellent, 92/100) then 20Mn5 (very good, 78/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20Mn5 and A285 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.