Background

Brasses are alloys of copper and zinc. They may also contain small amounts of other alloying elements to impart advantageous properties. Brasses have high corrosion resistance and high tensile strength. They are also suited to hot forging. Free machining grades of brass set the standard for machining, by which other metals are compared.
Brass Classes

Brasses are divided into two classes. The alpha alloys, with less than 37% zinc, and the alpha/beta alloys with 37-45% zinc. Alpha alloys are ductile and can be cold worked. Alpha/beta or duplex alloys have limited cold ductility and are harder and stronger. CZ108 is an alpha alloy.
Alloy CZ108

Brass alloy CZ108 is a high purity cold forming brass. It is used when severe bending or riveting properties are required. It can be machined but only with slow speeds and very light feeds.
Chemical Composition

Table 1. Typical chemical composition for brass alloy CZ108

%

CZ108

Cu

63

Pb

-

Sn

-

Fe

-

Al

-

Mn

-

Zn

Balance

Si

-

Ni

-

Properties
Mechanical Properties

Table 2. Typical mechanical properties for brass alloy CZ108

Grade

CZ108

Tensile Strength (Ann) MPa

275

Proof Stress 0.2% MPa

-

Elongation A5 (Ann) %

45

Hardness (Ann) VPN

80

Hardness (Half Hard) VPN

110

Hardness (EH) VPN

160
Physical Properties

Table 3. Typical physical properties for brass alloy CZ108

Property

Value

Density

8.44 g/cm3

Melting Point

916°C

Modulus of Elasticity

103.4 GPa

Thermal Conductivity

116 W/m.K at 20°C

Thermal Expansion

20.5×10-6 /°C at 20-300°C
Alloy Designations

CZ108 corresponds to the following designations:

CEN

BS

UNS

ISO

CW508L

CZ108

C27200

CZ108 is also sometimes referred to as yellow brass.
Corrosion Resistance

The corrosion resistance of CZ108 is excellent to good in most environments. It is not suited for use with acetic acid, moist ammonia or ammonia compounds, hydrochloric acid and nitric acid.
Fabrication
Cold Working

Cold working of CZ108 is excellent and it can be readily drawn.
Hot Working

Fabrication of CZ108 is rated as fair.
Welding and Joining

Soldering and brazing of CZ108 are both rated as “excellent”. Oxyacetylene welding is “good” and gas shielded methods are only “fair”. Resistance flash butt-welding may be done on rod, bar and wire.
Applications

CZ108 is typically used in:

· Nails

· Chains

· Screws

· Scientific Applications

· Radiators

· Heat Exchangers
Supplied Forms

CZ108 is typically supplied by Aalco in the following forms:

· Half Hard Tube

· Half Hard Sheet