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Steel 20Kh vs 4620

Steel · grade comparison

Steel 20Kh and 4620 are both steel grades. 4620 is the stronger of the two: yield strength 360 MPa (52.2 ksi) against 300 MPa (43.5 ksi) for 20Kh, about 20% more; tensile strength follows at 570 MPa (82.7 ksi) vs 490 MPa (71.1 ksi). On the shop floor, 20Kh sits in a lower cost tier (budget, $) than 4620 (standard, $$).

20KhChoose it when cost is the deciding factor.

4620Choose it when strength drives the design.

20Kh vs 4620: properties

20Kh4620

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

211 GPa30.6 Msi
205 GPa29.7 Msi

Shear Modulus

82 GPa11.9 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

490 MPa71.1 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
360 MPa52.2 ksi

Compressive Strength

300 MPa43.5 ksi
—

Shear Strength

320 MPa46.4 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

245 MPa35.5 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
—

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

156 HB
163 HB

Hardness, Rockwell B

82 HRB
84 HRB

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Elongation at Break 26% · Reduction in Area 55%

Physical

Density and transition temperatures.

Density

7.82 g/cm³0.28 lb/in³
7.85 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,460°C2,660 °F
1,420°C2,588 °F

Liquidus Temperature

1,510°C2,750 °F
1,500°C2,732 °F

Thermal

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

Thermal Conductivity

43 W/m·K24.8 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

466 J/kg·K0.11 BTU/lb·°F
475 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.6 µm/m·K6.4 µin/in·°F
11.9 µm/m·K6.6 µin/in·°F

Latent Heat of Fusion

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

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Same in both: Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.2 % IACS
8 % IACS

Electrical Resistivity

2.1×10⁻⁷ Ω·m8.27 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.61 V

Corrosion Resistance

11 / 100
12 / 100

Manufacturability

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

Machinability

60 / 100
57 / 100

Weldability

62 / 100
65 / 100

Formability (cold)

65 / 100
58 / 100

Castability

30 / 100
—

Brazeability / Solderability

65 / 100
70 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 65% · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
29 MJ/kg12,468 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

45 L/kg5.4 gal/lb
55 L/kg6.6 gal/lb

Typical Recycled Content

25%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

63 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

27 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

213 kJ/m³
316 kJ/m³

Thermal Diffusivity

11.8 mm²/s
12.3 mm²/s

Thermal Shock Resistance Index

9
11

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 scale462020Kh

Manufacturing and finishing

Capability20Kh4620
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$ 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.

20Kh vs 4620 — frequently asked

Is 4620 stronger than 20Kh?

Yes. 4620 has a typical yield strength of 360 MPa (52.2 ksi) against 300 MPa (43.5 ksi) for 20Kh — about 20% more. Tensile strength is 570 MPa (82.7 ksi) vs 490 MPa (71.1 ksi).

Which is cheaper, 20Kh or 4620?

20Kh is the lower-cost material: it sits in the budget tier ($) while 4620 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 20Kh over 4620?

Pick 20Kh when cost is the deciding factor. Pick 4620 when strength drives the design.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20Kh and 4620 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.