Linotype (alloy)

The Linotype alloy is a eutectic alloy of lead, antimony, and tin, historically used in the Linotype machine for hot metal typesetting. Its composition is typically around 85% lead, 12% antimony, and 3% tin, although the exact proportions can vary slightly depending on the manufacturer and specific application.

The low melting point of the Linotype alloy, approximately 464°F (240°C), was crucial for its use in the Linotype machine. This relatively low melting point allowed for rapid melting and solidification of the type characters within the machine, facilitating the high-speed production of lines of type.

The antimony content is essential for the alloy's expansion upon solidification, which allows the type to fill the mold sharply and produce a clean, crisp impression. Without antimony, the type would shrink upon cooling, resulting in poorly defined characters. The tin is added to improve the fluidity of the molten alloy and enhance its ability to cast fine details.

The Linotype alloy's properties also made it relatively durable, enabling the type to withstand the pressure of printing. After a printing run, the type metal could be melted down and reused, making the Linotype process economical.

Although the Linotype machine and its associated alloy are largely obsolete with the advent of phototypesetting and digital typography, the term "Linotype" remains historically significant in the printing industry. The properties of the alloy itself are also of interest to metallurgists and historians of technology.