Contact US

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!

*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

Brass Composition

Brass Composition

Brass Composition

I understand that there are a range of brasses, but is there any criteria that determines an amount of zinc that must be present for the copper alloy to be considered "brass"?  

RE: Brass Composition

Please take a look at Cu-Zn phase diagram to understand the solubility limits of Zn in Cu and the phase structure.

" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke

RE: Brass Composition

and you will see why all of the alloys called brass fall into the 15%-38% Zn range.
The low end is rather arbitrary.  Cu-Zn alloys with less than 15% Zn are usually called bronze.
The upper end is a phase structure limit.  There are alloys with more Zn, but they are not considered brasses.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

RE: Brass Composition


The ASTM B19 specification for Brass states that the composition is 68.5% - 71.5% copper, up to .07% lead, up to .05% iron and the remainder is zinc.

Hope this helps.


RE: Brass Composition

It might help if we knew why you are asking this question.
The most common brass is nominal 70% copper 30% zinc. It is also known as "cartridge brass".
This brass is subject to dezincification if left for long times in water. The Zn disappears, and the metal has a dull copper color, as copper is all that is left on the surface. You can see this in old plumbing fixtures, which used to be made of metal rather than plastic.
Brass with less than 15% zinc is supposed not to dezincify in water.
Copper with 5 or 6% zinc is called "gilding metal", and I believe was the chemistry of the US one cent coin prior to about 1980.
Just about anything that looks like brass will also stress corrode crack in ammonia, or nitrogen compounds that come from human or animal waste.

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


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. 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