Copper.

Tin.

Zinc.

Watch-makers brass.......................

1

part

-

2

parts

German brass.........................

1

"

-

1

"

Yellow brass...................

2

"

__

1

"

Speculum metal......................

2

"

1

part

Bell metal........................

3

"

1

"

Light castings and small bearings.................

4

"

1

"

"

Ditto a little harder......................

4

"

1

"

"

Heavy castings........................

6

to 7

1

"

1

"

Gun metal....................

9

"

1

"

-

The addition of a little lead makes the metal more easily wrought, and is advantageous when the work is not intended for exposure to heat.