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Steel M42 vs T1

Steel · grade comparison

Steel M42 and T1 are both steel grades, both tool steel. M42 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 560 MPa (81.2 ksi) for T1, about 11% more. In exchange, T1 is the more ductile: elongation 20% versus 12% for M42, and M42 is harder (255 HB vs 235 HB). M42 is lighter (7.98 g/cm³ vs 8.7 g/cm³ for T1). On the shop floor, T1 sits in a lower cost tier (premium, $$$) than M42 (specialty, $$$$$).

M42Choose it when strength drives the design, or when weight is the constraint.

T1Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

M42 vs T1: properties

M42T1

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

222 GPa32.2 Msi
220 GPa31.9 Msi

Shear Modulus

86 GPa12.5 Msi
84 GPa12.2 Msi

Tensile Strength (Ultimate)

900 MPa131 ksi
860 MPa125 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
560 MPa81.2 ksi

Elongation at Break

12%
20%

Reduction in Area

20%
32%

Compressive Strength

680 MPa98.6 ksi
1,400 MPa203 ksi

Shear Strength

545 MPa79 ksi
550 MPa79.8 ksi

Fatigue Strength (Endurance Limit)

400 MPa58 ksi
—

Fracture Toughness (K_IC)

33 MPa·√m30 ksi·√in
—

Charpy V-Notch Impact (RT)

9 J6.6 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

255 HB
235 HB

Hardness, Rockwell B

101 HRB
99 HRB

Hardness, Rockwell C

25 HRC
—

Hardness, Vickers

270 HV
245 HV

Same in both: Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.28

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,290°C2,354 °F
1,340°C2,444 °F

Liquidus Temperature

1,420°C2,588 °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
21 W/m·K12.1 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

—
250 J/g107 BTU/lb

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.5×10⁻⁷ Ω·m21.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

18 / 100
22 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.55 V

Manufacturability

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

Machinability

38 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

42%
30%

Weldability

20 / 100
15 / 100

Formability (cold)

10 / 100
15 / 100

Castability

20 / 100
25 / 100

Polishability

80 / 100
60 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

62 MJ/kg26,655 BTU/lb
52 MJ/kg22,356 BTU/lb

Embodied Carbon (primary production)

4.4 kg CO₂/kg
3.6 kg CO₂/kg

Typical Recycled Content

30%
45%

Same in both: Embodied Water 90 L/kg10.8 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

113 kN·m/kg
99 kN·m/kg

Specific Stiffness (E / density)

27.8 MN·m/kg
25.3 MN·m/kg

Modulus of Resilience

866 kJ/m³
713 kJ/m³

Thermal Diffusivity

6.6 mm²/s
5.7 mm²/s

Thermal Shock Resistance Index

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 scaleM42T1

Manufacturing and finishing

CapabilityM42T1
Default conditionAnnealedAnnealed
Relative cost$$$$$ Specialty$$$ Premium
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

M42 vs T1 — frequently asked

Is M42 stronger than T1?

Yes. M42 has a typical yield strength of 620 MPa (89.9 ksi) against 560 MPa (81.2 ksi) for T1 — about 11% more. Tensile strength is 900 MPa (131 ksi) vs 860 MPa (125 ksi).

Which is cheaper, M42 or T1?

T1 is the lower-cost material: it sits in the premium tier ($$$) while M42 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, M42 or T1?

M42. Its weldability rates poor (20/100) against poor (15/100) for T1.

Ready to make it?

Upload a CAD file and FabDigit prices the part in M42 and T1 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.