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Steel 50W800 vs M4

Steel · grade comparison

Steel 50W800 and M4 are both steel grades. M4 is the stronger of the two: yield strength 550 MPa (79.8 ksi) against 320 MPa (46.4 ksi) for 50W800, about 72% more; tensile strength follows at 880 MPa (128 ksi) vs 440 MPa (63.8 ksi). In exchange, 50W800 is the more ductile: elongation 28% versus 12% for M4, and M4 is harder (265 HV vs 150 HV). M4 is stiffer (217 GPa vs 205 GPa) and M4 runs hotter in service (400°C vs 200°C continuous). On the shop floor, 50W800 machines more easily (fair vs poor), 50W800 welds better (good vs poor), and 50W800 sits in a lower cost tier (budget, $) than M4 (specialty, $$$$$).

50W800Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

M4Choose it when strength drives the design, or when the part sees heat.

50W800 vs M4: properties

50W800M4

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
217 GPa31.5 Msi

Shear Modulus

80 GPa11.6 Msi
84 GPa12.2 Msi

Bulk Modulus

160 GPa23.2 Msi
165 GPa23.9 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

440 MPa63.8 ksi
880 MPa128 ksi

Yield Strength (0.2% offset)

320 MPa46.4 ksi
550 MPa79.8 ksi

Elongation at Break

28%
12%

Shear Strength

320 MPa46.4 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
—

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
—

Hardness, Rockwell B

78 HRB
—

Hardness, Vickers

150 HV
265 HV

Reduction in Area

—
25%

Compressive Strength

—
1,600 MPa232 ksi

Fracture Toughness (K_IC)

—
22 MPa·√m20 ksi·√in

Hardness, Brinell

—
250 HB

Hardness, Rockwell C

—
24 HRC

Physical

Density and transition temperatures.

Density

7.75 g/cm³0.28 lb/in³
7.97 g/cm³0.29 lb/in³

Melting Point (Solidus)

1,480°C2,696 °F
1,250°C2,282 °F

Liquidus Temperature

1,515°C2,759 °F
1,420°C2,588 °F

Thermal

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

Thermal Conductivity

30 W/m·K17.3 BTU/hr·ft·°F
22 W/m·K12.7 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
420 J/kg·K0.1 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12 µm/m·K6.7 µin/in·°F
11 µm/m·K6.1 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

200°C392 °F
400°C752 °F

Min Service Temperature

-40°C-40 °F
-60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

4.3 % IACS
2.9 % IACS

Electrical Resistivity

4×10⁻⁷ Ω·m15.7 µΩ·in
6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.58 V

Same in both: Corrosion Resistance 18 / 100

Manufacturability

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

Machinability

45 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
25%

Weldability

55 / 100
15 / 100

Formability (cold)

72 / 100
12 / 100

Castability

—
20 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
4.2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
110 L/kg13.2 gal/lb

Typical Recycled Content

20%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

57 kN·m/kg
110 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
27.2 MN·m/kg

Modulus of Resilience

250 kJ/m³
697 kJ/m³

Thermal Diffusivity

8.4 mm²/s
6.6 mm²/s

Thermal Shock Resistance Index

5
8

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 scaleM450W800

Manufacturing and finishing

Capability50W800M4
CNC machining—Yes
Default condition—Annealed
Relative cost$ Budget$$$$$ Specialty
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.

50W800 vs M4 — frequently asked

Is M4 stronger than 50W800?

Yes. M4 has a typical yield strength of 550 MPa (79.8 ksi) against 320 MPa (46.4 ksi) for 50W800 — about 72% more. Tensile strength is 880 MPa (128 ksi) vs 440 MPa (63.8 ksi).

Which is cheaper, 50W800 or M4?

50W800 is the lower-cost material: it sits in the budget tier ($) while M4 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 is easier to machine, 50W800 or M4?

50W800. Its machinability rates fair (45/100) against poor (25/100) for M4; for welding the order is 50W800 first (good, 55/100) then M4 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 50W800 and M4 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.