Bi-metal blades are a modern solution to cutting hard metals including steel. These blades are produced for many different styles of saws, including hacksaws, band saws, reciprocating saws and more. These blades last up to 10 times as long as traditional milled saw blades.
Before bi-metal blades were invented, saw blades were cut wholly from steel. But for more than 35 years bi-metal blades have been in use in all functions of cutting metal.
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How They Work
Bi-metal blades are, as their name suggests, made of two metals. These two metals, which are usually different types of steel are welded together. Spring steel is often used for backing and high-speed steel for edging.
Because of the welding process, which is usually done with an electron beam, weld teeth last longer and are able to cut through harder materials, such as steel, more easily.
While bi-metal blades can be used for many different materials, the most commonly used bi-metal blades are designed to cut different forms of metals. The determining factor is the teeth per inch; more teeth per inch (tpi) are used to cut harder materials.
Additions of new metals, such as chromium, and new bonding techniques, such as diffusion bonding, are adding strength and helping reduce heat. Heat especially is a damaging factor in blades and can break teeth off.