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Steel 17B2 vs 55Cr3

Steel · grade comparison

Steel 17B2 and 55Cr3 are both steel grades. 55Cr3 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 400 MPa (58 ksi) for 17B2, about 20% more; tensile strength follows at 800 MPa (116 ksi) vs 520 MPa (75.4 ksi). 55Cr3 is the more ductile: elongation 16% versus 13% for 17B2, and 55Cr3 is harder (225 HB vs 150 HB). 55Cr3 runs hotter in service (400°C vs 300°C continuous) and 17B2 conducts electricity better (9.5 % IACS vs 7.8 % IACS). On the shop floor, 17B2 welds better (very good vs poor) and 17B2 sits in a lower cost tier (budget, $) than 55Cr3 (standard, $$).

17B2Choose it when it will be welded, or when cost is the deciding factor.

55Cr3Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

17B2 vs 55Cr3: properties

17B255Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

520 MPa75.4 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
480 MPa69.6 ksi

Elongation at Break

13%
16%

Reduction in Area

55%
40%

Shear Strength

330 MPa47.9 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
360 MPa52.2 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

150 HB
225 HB

Hardness, Rockwell B

80 HRB
98 HRB

Hardness, Vickers

158 HV
236 HV

Compressive Strength

—
480 MPa69.6 ksi

Fracture Toughness (K_IC)

—
85 MPa·√m77.4 ksi·√in

Hardness, Rockwell C

—
20 HRC

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

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,495°C2,723 °F
1,420°C2,588 °F

Liquidus Temperature

1,520°C2,768 °F
1,490°C2,714 °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

47 W/m·K27.2 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
465 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F

Min Service Temperature

-20°C-4 °F
-40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.5 % IACS
7.8 % IACS

Electrical Resistivity

1.8×10⁻⁷ Ω·m7.09 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.61 V
—

Same in both: Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

58 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

68%
55%

Weldability

70 / 100
25 / 100

Formability (cold)

78 / 100
45 / 100

Brazeability / Solderability

70 / 100
40 / 100

Polishability

55 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Same in both: Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

66 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

386 kJ/m³
559 kJ/m³

Thermal Diffusivity

12.7 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

10
14

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 scale55Cr317B2

Manufacturing and finishing

Capability17B255Cr3
CNC machining—Yes
Sheet metal—Yes
Default condition—Annealed
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.

17B2 vs 55Cr3 — frequently asked

Is 55Cr3 stronger than 17B2?

Yes. 55Cr3 has a typical yield strength of 480 MPa (69.6 ksi) against 400 MPa (58 ksi) for 17B2 — about 20% more. Tensile strength is 800 MPa (116 ksi) vs 520 MPa (75.4 ksi).

Which is cheaper, 17B2 or 55Cr3?

17B2 is the lower-cost material: it sits in the budget tier ($) while 55Cr3 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, 17B2 or 55Cr3?

17B2. Its machinability rates good (58/100) against fair (50/100) for 55Cr3; for welding the order is 17B2 first (very good, 70/100) then 55Cr3 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 17B2 and 55Cr3 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.