Brinell hardness test

This MedLibrary.org supplementary page on Brinell hardness test is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:

Force diagram
Force diagram

The Brinell scale characterizes the indentation hardness of materials through the scale of penetration of an indenter, loaded on a material test-piece. It is one of several definitions of hardness in materials science.

Proposed by Swedish engineer Johan August Brinell in 1900, it was the first widely used and standardised hardness test in engineering and metallurgy. The large size of indentation and possible damage to test-piece limits its usefulness.

The typical test uses a 10 mm diameter steel ball as an indenter with a 3,000 kgf (29 kN) force. For softer materials, a smaller force is used; for harder materials, a tungsten carbide ball is substituted for the steel ball. The indentation is measured and hardness calculated as:

\mbox{BHN}=\frac{2P}{\pi D ({D-\sqrt{(D^2-d^2)})}}

where:

P = applied force (kgf)
D = diameter of indenter (mm)
d = diameter of indentation (mm)

Contents

Common values

When quoting a Brinell hardness number (BHN or more commonly HB), the conditions of the test used to obtain the number must be specified. The standard format for specifying tests can be seen in the example "HBW 10/3000". "HBW" means that a tungsten carbide (from the chemical symbol for tungsten) ball indenter was used, as opposed to "HBS", which means a hardened steel ball. The "10" is the ball diameter in millimeters. The "3000" is the force in kilograms force.

Brinell hardness numbers
Material Hardness
Softwood (e.g., pine) 1.6 HBS 10/100
Hardwood 2.6–7.0 HBS 1.6 10/100
Aluminium 15 HB
Copper 35 HB
Mild steel 120 HB
18-8 (304) stainless steel 1250 HB
Glass 1550 HB
Hardened tool steel 1500–1900 HB
Rhenium diboride 4600 HB
Note: Standard test conditions unless otherwise stated

Standards

  • International (ISO) and European (CEN) Standard
    • EN ISO 6506-1: Metallic materials - Brinell hardness test - Part 1: test method
    • EN ISO 6506-2: Metallic materials - Brinell hardness test - Part 2: verification and calibration of testing machine
    • EN ISO 6506-3: Metallic materials - Brinell hardness test - Part 3: calibration of reference blocks
  • US standard (ASTM International)
    • ASTM E10: Standard method for Brinell hardness of metallic materials.

See also

External links

Wikipedia content modification information:

  • This page was last modified on 2 October 2008, at 23:59.

Wikipedia Authorship and Review

Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.

Wikipedia Usage Guidelines

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Brinell hardness test".

The URL for this specific entry is:

All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.