FabDigit

SKH51 vs M42 and 2 more: properties

SKH51M42T8T1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

217 GPa31.5 Msi
222 GPa32.2 Msi
220 GPa31.9 Msi
220 GPa31.9 Msi

Shear Modulus

84 GPa12.2 Msi
86 GPa12.5 Msi
85 GPa12.3 Msi
84 GPa12.2 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi
170 GPa24.7 Msi
165 GPa23.9 Msi

Poisson's Ratio

0.28
0.28
0.29
0.28

Tensile Strength (Ultimate)

850 MPa123 ksi
900 MPa131 ksi
900 MPa131 ksi
860 MPa125 ksi

Yield Strength (0.2% offset)

550 MPa79.8 ksi
620 MPa89.9 ksi
570 MPa82.7 ksi
560 MPa81.2 ksi

Elongation at Break

20%
12%
15%
20%

Reduction in Area

35%
20%
25%
32%

Compressive Strength

900 MPa131 ksi
680 MPa98.6 ksi
1,200 MPa174 ksi
1,400 MPa203 ksi

Shear Strength

560 MPa81.2 ksi
545 MPa79 ksi
550 MPa79.8 ksi

Fatigue Strength (Endurance Limit)

380 MPa55.1 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

30 MPa·√m27.3 ksi·√in
33 MPa·√m30 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
9 J6.6 ft·lbf
25 J18.4 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

240 HB
255 HB
240 HB
235 HB

Hardness, Rockwell B

99 HRB
101 HRB
99 HRB
99 HRB

Hardness, Rockwell C

22 HRC
25 HRC

Hardness, Vickers

250 HV
270 HV
250 HV
245 HV

Physical

Density and transition temperatures.

Density

8.16 g/cm³0.29 lb/in³
7.98 g/cm³0.29 lb/in³
8.6 g/cm³0.31 lb/in³
8.7 g/cm³0.31 lb/in³

Melting Point (Solidus)

1,370°C2,498 °F
1,290°C2,354 °F
1,400°C2,552 °F
1,340°C2,444 °F

Liquidus Temperature

1,450°C2,642 °F
1,420°C2,588 °F
1,460°C2,660 °F
1,440°C2,624 °F

Thermal

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

Thermal Conductivity

22 W/m·K12.7 BTU/hr·ft·°F
22 W/m·K12.7 BTU/hr·ft·°F
22 W/m·K12.7 BTU/hr·ft·°F
21 W/m·K12.1 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11 µm/m·K6.1 µin/in·°F
10.8 µm/m·K6 µin/in·°F
11.2 µm/m·K6.2 µin/in·°F
11 µm/m·K6.1 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
250 J/g107 BTU/lb
250 J/g107 BTU/lb

Min Service Temperature

-60°C-76 °F
-60°C-76 °F
-40°C-40 °F
-60°C-76 °F

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
3.1 % IACS
3.1 % IACS
3.1 % IACS

Electrical Resistivity

5.9×10⁻⁷ Ω·m23.2 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in
5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

16 / 100
18 / 100
18 / 100
22 / 100

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.55 V

Manufacturability

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

Machinability

30 / 100
38 / 100
35 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

35%
42%
40%
30%

Weldability

20 / 100
20 / 100
15 / 100
15 / 100

Formability (cold)

15 / 100
10 / 100
12 / 100
15 / 100

Castability

25 / 100
20 / 100
25 / 100

Polishability

70 / 100
80 / 100
70 / 100
60 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

45 MJ/kg19,347 BTU/lb
62 MJ/kg26,655 BTU/lb
60 MJ/kg25,795 BTU/lb
52 MJ/kg22,356 BTU/lb

Embodied Carbon (primary production)

3.2 kg CO₂/kg
4.4 kg CO₂/kg
4.2 kg CO₂/kg
3.6 kg CO₂/kg

Embodied Water

70 L/kg8.4 gal/lb
90 L/kg10.8 gal/lb
90 L/kg10.8 gal/lb
90 L/kg10.8 gal/lb

Typical Recycled Content

45%
30%
35%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

104 kN·m/kg
113 kN·m/kg
105 kN·m/kg
99 kN·m/kg

Specific Stiffness (E / density)

26.6 MN·m/kg
27.8 MN·m/kg
25.6 MN·m/kg
25.3 MN·m/kg

Modulus of Resilience

697 kJ/m³
866 kJ/m³
738 kJ/m³
713 kJ/m³

Thermal Diffusivity

6.4 mm²/s
6.6 mm²/s
6.1 mm²/s
5.7 mm²/s

Thermal Shock Resistance Index

8
8
8
7

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 scaleM42T8T1SKH51

Manufacturing and finishing

CapabilitySKH51M42T8T1
CNC machiningYesYesYes
Default conditionAnnealedAnnealedAnnealed
Relative cost$$$ Premium$$$$$ Specialty$$$ Premium$$$ Premium
Min. machined wall0.8 mm0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µmRa 1.6 µm
AlCrNYesYesYes
AlTiNYesYesYes
Black OxideYesYesYes
CVD Al2O3YesYesYes
CVD TiCNYesYesYes
CVD TiNYesYesYes
CerakoteYesYesYes
Chrome PlatingYesYesYes
CrNYesYesYes
DLCYesYesYes
E-CoatingYesYesYes
HVOF CoatingYesYesYes
Hot-Dip GalvanizingYesYesYes
MoS2YesYesYes
Multilayer CVDYesYesYes
Nickel PlatingYesYesYes
PTFE CoatingYesYesYes
PaintingYesYesYes

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

Ready to make it?

Upload a CAD file and FabDigit prices the part in SKH51 and M42 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.