FabDigitFabDigit

Steel 15Kh vs 4620

Steel · grade comparison

Steel 15Kh and 4620 are both steel grades. 15Kh is the stronger of the two: yield strength 540 MPa (78.3 ksi) against 360 MPa (52.2 ksi) for 4620, about 50% more; tensile strength follows at 750 MPa (109 ksi) vs 570 MPa (82.7 ksi). In exchange, 4620 is the more ductile: elongation 26% versus 14% for 15Kh, and 15Kh is harder (217 HB vs 163 HB). 4620 runs hotter in service (400°C vs 200°C continuous). On the shop floor, 4620 machines more easily (good vs fair), 4620 welds better (65 vs 55 out of 100), and 15Kh sits in a lower cost tier (budget, $) than 4620 (standard, $$).

15KhChoose it when strength drives the design, or when cost is the deciding factor.

4620Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

15Kh vs 4620: properties

15Kh4620

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

212 GPa30.7 Msi
205 GPa29.7 Msi

Shear Modulus

82 GPa11.9 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

750 MPa109 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

540 MPa78.3 ksi
360 MPa52.2 ksi

Elongation at Break

14%
26%

Reduction in Area

50%
55%

Shear Strength

460 MPa66.7 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
—

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
85 J62.7 ft·lbf

Hardness, Brinell

217 HB
163 HB

Hardness, Rockwell C

20 HRC
—

Hardness, Vickers

228 HV
—

Hardness, Rockwell B

—
84 HRB

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Same in both: Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
475 J/kg·K0.11 BTU/lb·°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
-50°C-58 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°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

10 / 100
12 / 100

Manufacturability

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

Machinability

45 / 100
57 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
65%

Weldability

55 / 100
65 / 100

Formability (cold)

60 / 100
58 / 100

Castability

30 / 100
—

Brazeability / Solderability

65 / 100
70 / 100

Same in both: 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

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

96 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

27.1 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

688 kJ/m³
316 kJ/m³

Thermal Diffusivity

11.4 mm²/s
12.3 mm²/s

Thermal Shock Resistance Index

12
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 scale462015Kh

Manufacturing and finishing

Capability15Kh4620
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.

15Kh vs 4620 — frequently asked

Is 15Kh stronger than 4620?

Yes. 15Kh has a typical yield strength of 540 MPa (78.3 ksi) against 360 MPa (52.2 ksi) for 4620 — about 50% more. Tensile strength is 750 MPa (109 ksi) vs 570 MPa (82.7 ksi).

Which is cheaper, 15Kh or 4620?

15Kh 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.

Which is easier to machine, 15Kh or 4620?

4620. Its machinability rates good (57/100) against fair (45/100) for 15Kh; for welding the order is 4620 first (good, 65/100) then 15Kh (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 15Kh 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.