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Steel 34CrAlNi7-10 vs SACM645

Steel · grade comparison

Steel 34CrAlNi7-10 and SACM645 are both steel grades. 34CrAlNi7-10 is the stronger of the two: tensile strength 1,000 MPa (145 ksi) against 950 MPa (138 ksi) for SACM645, about 5% more. In exchange, SACM645 is the more ductile: elongation 17% versus 13% for 34CrAlNi7-10, and 34CrAlNi7-10 is harder (310 HB vs 270 HB). 34CrAlNi7-10 runs hotter in service (500°C vs 450°C continuous) and SACM645 conducts electricity better (7.5 % IACS vs 6.6 % IACS).

34CrAlNi7-10Choose it when strength drives the design, or when the part sees heat.

SACM645Choose it when the part is bent, formed or impact-loaded.

34CrAlNi7-10 vs SACM645: properties

34CrAlNi7-10SACM645

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
207 GPa30 Msi

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

1,000 MPa145 ksi
950 MPa138 ksi

Elongation at Break

13%
17%

Reduction in Area

50%
55%

Compressive Strength

800 MPa116 ksi
790 MPa115 ksi

Shear Strength

620 MPa89.9 ksi
570 MPa82.7 ksi

Fatigue Strength (Endurance Limit)

480 MPa69.6 ksi
430 MPa62.4 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
75 J55.3 ft·lbf

Hardness, Brinell

310 HB
270 HB

Hardness, Rockwell C

33 HRC
28 HRC

Hardness, Vickers

325 HV
285 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Poisson's Ratio 0.29 · Yield Strength (0.2% offset) 780 MPa113 ksi · Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,400°C2,552 °F
1,425°C2,597 °F

Liquidus Temperature

1,480°C2,696 °F
1,490°C2,714 °F

Same in both: Density 7.8 g/cm³0.28 lb/in³

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.6 µm/m·K6.4 µin/in·°F
12.2 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

500°C932 °F
450°C842 °F

Same in both: Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

6.6 % IACS
7.5 % IACS

Electrical Resistivity

2.6×10⁻⁷ Ω·m10.2 µΩ·in
2.3×10⁻⁷ Ω·m9.06 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

16 / 100
15 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

45 / 100
42 / 100

Weldability

12 / 100
18 / 100

Formability (cold)

20 / 100
25 / 100

Brazeability / Solderability

25 / 100
40 / 100

Polishability

70 / 100
60 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 45%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.5 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
55 L/kg6.6 gal/lb

Typical Recycled Content

25%
28%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

128 kN·m/kg
122 kN·m/kg

Specific Stiffness (E / density)

26.9 MN·m/kg
26.5 MN·m/kg

Modulus of Resilience

1,449 kJ/m³
1,470 kJ/m³

Thermal Diffusivity

9.2 mm²/s
9.9 mm²/s

Same in both: Thermal Shock Resistance Index 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 scaleSACM64534CrAlNi7-10

Manufacturing and finishing

Capability34CrAlNi7-10SACM645
CNC machining—Yes
Sheet metal—Yes
Default condition—Q&T
Relative cost$$ Standard$$ 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.

34CrAlNi7-10 vs SACM645 — frequently asked

Is 34CrAlNi7-10 stronger than SACM645?

Yes. 34CrAlNi7-10 has a typical tensile strength of 1,000 MPa (145 ksi) against 950 MPa (138 ksi) for SACM645 — about 5% more.

Which is cheaper, 34CrAlNi7-10 or SACM645?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which welds better, 34CrAlNi7-10 or SACM645?

SACM645. Its weldability rates poor (18/100) against not recommended (12/100) for 34CrAlNi7-10.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34CrAlNi7-10 and SACM645 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.