SAE 4120 Properties ⚙️ (Chem., Mech. & Rankings) rev. 2022

 

In this post I'll talk about SAE 4120. First let's describe it and then have a look at its material's properties.

What is SAE 4120?

SAE 4120 is a chromium-molybdenum steel with, approximately, 0.20% carbon content.

Application

They are used in oil and gas, energy, construction and the automotive industries because of its corrosion resistance and high-temperature and tensile strength.

UNS Number

G41200

Ok let's start with SAE 4120 Chemical Composition.

Chemical Composition

C, Carbon

0.18–0.23

Mn, Manganese

0.90–1.20

P, Phosphorus max.

0.035

S, Sulfur max.

0.040

Si, Silicon

0.15–0.35

Cr, Chromium

0.40–0.60

Mo, Molybdenum

0.13–0.20

Learn more about Chemical Composition.

Now it's the mechanical properties turn:

Yield Strength

685 MPa

Learn more about Yield Strength.

Tensile Strength

885 MPa

Learn more about Tensile Strength.

Elongation (min.)

0,12.

Learn more about Elongation.

Reduction of Area (min. %)

0,5.

Learn more about Reduction of Area.

Density

7.7 - 8.03 g/cm3.

Learn more about Density.

Elastic Modulus

190-210 GPa.

Learn more about Elastic Modulus.

Poisson's ratio

0.27 - 0.30.

Learn more about Poisson's ratio.

Allowable Stress or Factor of Safety

Depends on the project (And its factor of safety).

Learn more about Allowable Stress or Factor of Safety.

My Material's Ranking Research

While engineers will often look for the cheapest material they can use, I took a different approach to material's selection to help newbie students.

I ranked materials according to their yield strengths and SAE 4120 currently ranks 10 in my yield strength index. This means there are other 9 materials that are more resistant.

Note: I've analysed 162 materials in order to create an yield strength index. Check my material's comparison post for more details.

SAE Classroom

Are you having trouble understanding the basics of SAE?

What is SAE: Classification and specification?

This video will walk you through:

References

ASTM A29 and other references.

Citation

When you need to include a fact or piece of information in an assignment or essay you should also include where and how you found that piece of information.

That gives credibility to your paper and it is sometimes required in higher education.

To make your life (and citation) easier just copy and paste the information below into your assignment or essay:

Luz, Gelson. SAE 4120 Properties (Chem., Mech. & Rankings). Materials Blog. Gelsonluz.com. dd mmmm. yyyy. URL

Now replace dd, mmmm and yyyy with the day, month, and year you browsed this page. Also replace URL for the actual url of this page. This citation format is based on MLA.