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Steel 100Cr6 vs SUJ1

Steel · grade comparison

Steel 100Cr6 and SUJ1 are both steel grades. Both yield at about 420 MPa — strength does not separate them. 100Cr6 is harder — 200 HB against 190 HB for SUJ1 — which matters for wear surfaces and threads. 100Cr6 runs hotter in service (200°C vs 150°C continuous) and 100Cr6 conducts electricity better (8 % IACS vs 6.5 % IACS). On the shop floor, SUJ1 forms better (45 vs 35 out of 100) and SUJ1 sits in a lower cost tier (budget, $) than 100Cr6 (standard, $$).

100Cr6Choose it when surface hardness matters, or when the part sees heat.

SUJ1Choose it when cost is the deciding factor.

100Cr6 vs SUJ1: properties

100Cr6SUJ1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Poisson's Ratio

0.29
0.3

Yield Strength (0.2% offset)

420 MPa60.9 ksi
400 MPa58 ksi

Reduction in Area

48%
45%

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
320 MPa46.4 ksi

Hardness, Brinell

200 HB
190 HB

Hardness, Rockwell B

94 HRB
91 HRB

Hardness, Vickers

210 HV
198 HV

Compressive Strength

—
420 MPa60.9 ksi

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Tensile Strength (Ultimate) 660 MPa95.7 ksi · Elongation at Break 22% · Shear Strength 400 MPa58 ksi · Charpy V-Notch Impact (RT) 25 J18.4 ft·lbf

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,424°C2,595 °F
1,400°C2,552 °F

Liquidus Temperature

1,455°C2,651 °F
1,460°C2,660 °F

Same in both: Density 7.81 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
150°C302 °F

Min Service Temperature

-40°C-40 °F
-60°C-76 °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 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
6.5 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.7×10⁻⁷ Ω·m10.6 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

45 / 100
42 / 100

Formability (cold)

35 / 100
45 / 100

Brazeability / Solderability

45 / 100
35 / 100

Polishability

88 / 100
80 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 40% · Weldability 12 / 100 · Castability 30 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
29 MJ/kg12,468 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

65 L/kg7.8 gal/lb
55 L/kg6.6 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Modulus of Resilience

420 kJ/m³
381 kJ/m³

Thermal Diffusivity

12.3 mm²/s
12.5 mm²/s

Same in both: Specific Strength (UTS / density) 85 kN·m/kg · Specific Stiffness (E / density) 26.9 MN·m/kg · Thermal Shock Resistance Index 12

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 scale100Cr6SUJ1

Manufacturing and finishing

Capability100Cr6SUJ1
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$ Standard$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

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

100Cr6 vs SUJ1 — frequently asked

What is the difference between 100Cr6 and SUJ1?

Steel 100Cr6 and SUJ1 are both steel grades. Both yield at about 420 MPa — strength does not separate them. 100Cr6 is harder — 200 HB against 190 HB for SUJ1 — which matters for wear surfaces and threads.

Which is cheaper, 100Cr6 or SUJ1?

SUJ1 is the lower-cost material: it sits in the budget tier ($) while 100Cr6 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

When should I choose 100Cr6 over SUJ1?

Pick 100Cr6 when surface hardness matters, or when the part sees heat. Pick SUJ1 when cost is the deciding factor.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 100Cr6 and SUJ1 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.