ASTM A691 Properties⚙️ (Chem., Mech. & Rankings) rev. 2022

In this post I'll talk about and give details about ASTM A691. First let's describe it and then have a look at its material's properties.

What is ASTM A691?

ASTM A691 is a Specification for Carbon and Alloy Steel Pipe, Electric-Fusion-Welded for High-Pressure Service at High Temperatures.


Corrosion-Resisting and Heat-Resisting Steels


This specification covers carbon and alloy steel pipe, electric-fusion-welded with filler metal added, fabricated from pressure-vessel-quality plate of several analyses and strength levels and suitable for high-pressure service at high temperatures.

Ok let's start with ASTM A691 chemical composition.

Chemical Composition

Grade 91


0.08 - 0.12


0.30 - 0.60

P max.


S max.



0.20 - 0.50


8.00 - 9.50


0.85 - 1.05

Ni max.



0.18 - 0.25


0.06 - 0.10


0.030 - 0.070

Al max.


Tin max.


Zr max.


Learn more about chemical composition.

Now it's the mechanical properties turn:

Tensile Strength

Grade 91

85 - 110 ksi (585 - 760 MPa)

Learn more about what is tensile strength.

Elongation (min.) 50 mm


Learn more about what is elongation.

Reduction of Area (min. %)

Not Required.

Learn more about reduction of area.

Hardness Requirements

Grade 91

241 HB max.

Learn more about what is hardness.

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 A691 currently ranks 166 in my yield strength index. This means there are other 165 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.

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:



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 A691 Properties (Chem., Mech. & Rankings). Materials Blog. 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 20/A 20M Specification for General Requirements for⁣
Steel Plates for Pressure Vessels⁣
A 204/A 204M Specification for Pressure Vessel Plates,⁣
Alloy Steel, Molybdenum⁣
A 299/A 299M Specification for Pressure Vessel Plates,⁣
Carbon Steel, Manganese-Silicon⁣
A 370 Test Methods and Definitions for Mechanical Testing⁣
of Steel Products⁣
A 387/A 387M Specification for Pressure Vessel Plates,⁣
Alloy Steel, Chromium-Molybdenum⁣
A 435/A 435M Specification for Straight-Beam Ultrasonic⁣
Examination of Steel Plates⁣
A 530/A 530M Specification for General Requirements⁣
for Specialized Carbon and Alloy Steel Pipe⁣
A 537/A 537M Specification for Pressure Vessel Plates,⁣
Heat-Treated, Carbon-Manganese-Silicon Steel⁣
E 165 Practice for Liquid Penetrant Inspection Method⁣
E 350 Methods for Chemical Analysis of Carbon Steel,⁣
Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron,⁣
and Wrought Iron⁣
E 709 Practice for Magnetic Particle Examination⁣



Materials: ASTM A691 Properties⚙️ (Chem., Mech. & Rankings) rev. 2022
ASTM A691 Properties⚙️ (Chem., Mech. & Rankings) rev. 2022
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS PREMIUM CONTENT IS LOCKED STEP 1: Share to a social network STEP 2: Click the link on your social network Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy Table of Content