VI.—Tin, 53 parts; lead, 43 parts; antimony, 4 parts.
Hard lead is made of lead, 84 parts; antimony, 16 parts.
Sheet Metal Alloy.—
| Tin | 35 parts |
| Lead | 250 parts |
| Copper | 2.5 parts |
| Zinc | 0.5 part |
This alloy has a fine white color, and can be readily rolled into thin sheets. For that reason it is well adapted for lining tea chests and for the production of tobacco and chocolate wrappers. The copper and zinc are used in the form of fine shavings. The alloy should be immediately cast into thin plates, which can then be passed through rolls.
Magnetic Alloys.
Alloys which can be magnetized most strongly are composed of copper, manganese, and aluminum, the quantities of manganese and aluminum being proportional to their atomic weights (55.0 to 27.1, or about 2 to 1). The maximum magnetization increases rapidly with increase of manganese, but alloys containing much manganese are exceedingly brittle and cannot be wrought. The highest practicable proportion of manganese at present is 24 per cent.
These magnetic alloys were studied by Hensler, Haupt, and Starck, and Gumlich has recently examined them at the Physikalisch—technische Reichsanstalt, with very remarkable and interesting results.
The two alloys examined were composed as follows:
Alloy I.—Copper, 61.5 per cent; manganese, 23.5 per cent; aluminum, 15 per cent; lead, 0.1 per cent, with traces of iron and silicon.