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

Black Locust Design Values

Black Locust Design Values

Black Locust Design Values

I have an Arch. that wants to use 2x Black Locust for decking. My job is to figure out how far we can span it with Assembly loads. The info on the internet is pretty slim. I found this:

Gives the MOR of 19.4 ksi. Does anyone know how to convert that to an allowable bending stress?


RE: Black Locust Design Values

XR250....Check Chapter 4 of The Wood Handbook. Available online at following link....

Chapter 4

RE: Black Locust Design Values

Thanks Ron,

That gives me the same ol' 19.4 ksi value. Looks like there is a factor of safety of about 5.0 on the values based on what I use for pine. I may just use 3 ksi. Serviceability may control anyway
The decking is a literally 4 inches off the ground on sleepers so I don't know that I really should worry about strength :>

RE: Black Locust Design Values

XR250....MR is fb at ultimate failure, so I don't see an issue with using the pine values or with using the ratio of pine values (MR for pine relative to allowable fb for pine).

RE: Black Locust Design Values

Thanks Ron

RE: Black Locust Design Values

I don't have the design values for you to use, but I can tell you that black locust is multiples of the strength of any softwood used to produce decking and showing in any set of tables. It's harder, stronger, and tougher. Anyone milling oak would tell you that red oak is softer and weaker and white oak is comparable if they did a comparison, but the toughness is in a completely other realm. I don't know how that translates into allowable stresses, but I'd have no qualms using D-fir or Larch values and being confident that it was very conservative.

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! Already a Member? Login


White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each person’s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now
White Paper - Medical Device Design Control
Medical device product development is a highly integrated and regulated process. Implementation of a requirements tracking solution requires attention to a variety of nuanced topics. When presented with the task of tracking the many concept relationships in a project of this type, the initial software solution of choice tends to be a two-dimensional text systems. Download Now

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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close