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Steel 17Cr3 vs 55Cr3

Steel · grade comparison

Steel 17Cr3 and 55Cr3 are both steel grades. 55Cr3 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 360 MPa (52.2 ksi) for 17Cr3, about 33% more; tensile strength follows at 800 MPa (116 ksi) vs 590 MPa (85.6 ksi). In exchange, 17Cr3 is the more ductile: elongation 20% versus 16% for 55Cr3, and 55Cr3 is harder (225 HB vs 170 HB). 55Cr3 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 17Cr3 machines more easily (good vs fair), 17Cr3 welds better (good vs poor), and 17Cr3 sits in a lower cost tier (budget, $) than 55Cr3 (standard, $$).

17Cr3Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

55Cr3Choose it when strength drives the design, or when the part sees heat.

17Cr3 vs 55Cr3: properties

17Cr355Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

590 MPa85.6 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
480 MPa69.6 ksi

Elongation at Break

20%
16%

Reduction in Area

50%
40%

Compressive Strength

370 MPa53.7 ksi
480 MPa69.6 ksi

Shear Strength

400 MPa58 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

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

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

170 HB
225 HB

Hardness, Rockwell B

87 HRB
98 HRB

Hardness, Vickers

180 HV
236 HV

Hardness, Rockwell C

—
20 HRC

Same in both: Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,495°C2,723 °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.

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)

11.8 µm/m·K6.6 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)

350°C662 °F
400°C752 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7.8 % IACS

Electrical Resistivity

2.1×10⁻⁷ Ω·m8.27 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)

-0.6 V
—

Corrosion Resistance

13 / 100
10 / 100

Manufacturability

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

Machinability

62 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
55%

Weldability

60 / 100
25 / 100

Formability (cold)

55 / 100
45 / 100

Castability

25 / 100
—

Brazeability / Solderability

65 / 100
40 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

50 L/kg6 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

75 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

309 kJ/m³
559 kJ/m³

Thermal Diffusivity

11.9 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 scale55Cr317Cr3

Manufacturing and finishing

Capability17Cr355Cr3
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.

17Cr3 vs 55Cr3 — frequently asked

Is 55Cr3 stronger than 17Cr3?

Yes. 55Cr3 has a typical yield strength of 480 MPa (69.6 ksi) against 360 MPa (52.2 ksi) for 17Cr3 — about 33% more. Tensile strength is 800 MPa (116 ksi) vs 590 MPa (85.6 ksi).

Which is cheaper, 17Cr3 or 55Cr3?

17Cr3 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, 17Cr3 or 55Cr3?

17Cr3. Its machinability rates good (62/100) against fair (50/100) for 55Cr3; for welding the order is 17Cr3 first (good, 60/100) then 55Cr3 (poor, 25/100).

Ready to make it?

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