ASTM A668 Properties⚙️ (Chem., Mech. & Rankings) rev. 2022

In this post I'll talk about and give details about ASTM A668. First let's describe it and then have a look at its material's properties.

What is ASTM A668?

ASTM A668 is a Specification for Steel Forgings, Carbon and Alloy, for General Industrial Use

Category

Steel Forgings

Scope

This specification covers untreated and heat-treated carbon and alloy steel forgings for general industrial use. Other ASTM specifications for forgings are available for specific applications such as pressure vessels, railroad use, turbine generators, gearing, and others involving special temperature requirements.

Ok let's start with ASTM A668 chemical composition.

Chemical Composition

Class A to F and AH to FH

Mn max.

1.35

P max.

0.050

S max.

0.050

Learn more about chemical composition.

Now it's the mechanical properties turn:

Yield Strength

Class D (Up to 200mm)

37500 psi (260 MPa) min.

Learn more about what is yield strength.

Tensile Strength

Class D (Up to 200mm)

75000 psi (515 MPa) min.

Learn more about what is tensile strength.

Elongation (min.) 50 mm

0.24.

Learn more about what is elongation.

Reduction of Area (min. %)

0.4.

Learn more about reduction of area.

Hardness Requirements

Class D (Up to 200mm)

149 - 207 HB

Learn more about what is hardness.

Density

7800 - 8000 kg/m3 (around 7.9 g/cm3 or 0.285 lb/in3).

Learn more about density.

Elastic Modulus

190 GPa (27557 ksi) - 210GPa (30458 ksi).

Learn more about the Elastic Modulus.

Poisson's Ratio

0.27 – 0.30.

Learn more about the poisson ratio.

Allowable Stress

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

Learn more about the what is allowable stress.

My Material's Rank

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 ASTM A668 currently ranks 76 in my yield strength index. This means there are other 75 materials that are more resistant.

Note: I've analysed 134 materials in order to create an yield strength index. Check my astm material's comparison post for more details.

Details and PDF

Instructions:

1. Go to this page.
2. Type the name of the standard you are looking for in the search box. Tip: Don't forget to include "ASTM" as a keyword.
3. Read the details about the standard or download the PDF.

ASTM Classroom

Are you having trouble understanding the basics of ASTM?

What is the difference between Code, Standard & Specification?

This video will walk you through:

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 & paste the information below into your assignment or essay:

Luz, Gelson. ASTM A668 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 (The < and > stay, ok?). This citation format is based on MLA.

Other References

A 275/A 275M Test Method for Magnetic Particle Examination⁣
of Steel Forgings⁣
A 370 Test Methods and Definitions for Mechanical Testing⁣
of Steel Products⁣
A 388/A 388M Practice for Ultrasonic Examination of⁣
Heavy Steel Forgings⁣
A 788 Specification for Steel Forgings, General Requirements⁣
E 381 Method of Macroetch Testing Steel Bars, Billets,⁣
Blooms, and Forgings⁣