×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

#### Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
To Your Posts
• Keyword Search
• One-Click Access To Your
Favorite Forums
• Automated Signatures
On Your Posts
• Best Of All, It's Free!
• Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

# Question on a certain calculation

 Forum Search FAQs Links MVPs

## Question on a certain calculation

(OP)
I have a question on a certain calculation in the
Design of Anchor Reinforcement in Concrete Pedestals by Widianto, Patel and Owen.... I found it in google and I also uploaded this on the link below,

my question is that on page 14 of the article, there's a formula involving the bearing area:

Abrg = 0.866*2^2-5/4 * 1.25^2

i know that "2" came from the anchor head, and "1.25" is the diameter of anchor, but where did they get the "0.866" and "5/4" respectively?

thank you in advance!

Poems are made by fools like me, but only God can make a tree. engineers creates wonderful buildings, but only God can creates wonderful minds

### RE: Question on a certain calculation

There's a typo in the formula and it affects the answer.  It should be pi/4, not 5/4. The bearing area of a 1.25 diameter bolt with a heavy hex head is 2.237 in^2.
As far as the .866, I don't have the formula in front of me, but that must be the factor to calculate the area of a hexagon.

### RE: Question on a certain calculation

I can confirm JedClampett's statement:

for a Hexagon, A = 0.866*d^2

d = distance across the flats.

chichuck

### RE: Question on a certain calculation

(OP)
thank you very much

Poems are made by fools like me, but only God can make a tree. engineers creates wonderful buildings, but only God can creates wonderful minds

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

### Reply To This Thread

#### Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!

Already a member? Close this window and log in.