This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.

Clubs, glossaries, museums, shops and much more......

...all of your model making needs from one site.

Model Engineering Glossary: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Brass is an alloy of copper and zinc, but often other elements such as aluminium, iron, manganese, tin and lead are added.

There are two basic classes of brass:

  1. Alpha alloys - less than 37% zinc - ductile and can be cold worked.
  2. alpha/beta or duplex alloys - 37-45% zinc - have limited cold ductility and are harder and stronger.

British Standards:

  • CZ101
  • CZ108 Brass - A common, high purity brass alloy suited to many general applications and often used used in general electrical engineering (sheet/strip products). Hardness and strength are both excellent and this alloy is well suited to cold forming.
  • CZ112 Naval Brass - added tin gives better corrosion resistance.
  • CZ116 Higher Tensile Brass
  • CZ121 Free Machining Brass - cold working is poor.
  • CZ126 Arsenical Brass - increased resistance to corrosion. Its ductility and strength is better than other common alloys.
  • CZ131 Turning and Riveting Brass

Material properties:

Density kg/m3 8400 to 8600
Modulus of elasticity E GPa 96 to 110
Modulus of elasticity G GPa 36 to 41
Poisson's ratio v 0.34
Note: These properties should be used for indication only as material properties vary from sample to sample.
Yellow brass
An American term for 67/33 or 65/35 brass.

The larger gears for the 4-cycle solenoid V-twin machined from brass and designed to run against steel smaller drive gear.

Brass can be machined very crisp.


Bronze and brass are very similar when machining. TCT tools work very well with a very shallow back and side rake (see Lathe Tools).

We reviewed the Glanze TCT tools.

These tools have a steel body with separate TCT bits that are pre-machined to the correct angles. When the bit wears out or gets chipped then you just replace it.

Note that when machining rough castings it is very easy to chip the tools, so take that into account and use small cuts at first.


If you want a very bright finish then use a very fine wet and dry paper and then finish with wire wool. Note that brass tarnishes quite quickly and so you will either have to buff regularly or use a lacquer.

See also: Bronze.

Model Engineering Glossary: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z