The cold saw is a tool that’s been growing in popularity because of the number of different things it can do. Originally made for cutting metal, there are now portable versions which have greatly enhanced the versatility of the cold saw. The name of the tool comes from the way heat is transferred in the cutting process so both the blade and the material being cut remain cool. There are two types of blade that can be used with the cold saw. These are the high speed steel blade and the tungsten carbide tipped blade.
Cold saws actually cost less per cut than other type of saw because of their efficiency and accuracy in cutting. This means they’re ideal for high production environments, particularly because the blades last a long time and can be resharpened on several occasions before they have to be replaced.
There are also portable cold saws which have proved to be popular among sheet metal roofers because they don’t take the protective coating off the metal. They can also cut through thicknesses of up to ¼ inch.
High Speed Steel Blade
The high speed steel (or HSS) blade is a bit of a misnomer because it doesn’t run at particularly high speeds at all. In fact, it usually runs slower than other cold saw blades. They’re sometimes coated with titanium nitride to give them added strength. The blade itself is made from a specific type of tool steel, either M2 or M35, that has cobalt as an additional alloy. After heat treatment, the blades are hardened which means they won’t wear out very easily. Unfortunately, it does leave them brittle so you have to have the correct blade, with the right number of teeth per inch, for each job.
High speed steel cold saw blades tend to be used on metal items such as ingots and castings. However, if they haven’t been properly press quenched during the manufacturing process, they can end up warped. They also are noted for their poor levels of shock-resistance.
High speed steel blades can be resharpened quite a number of times before they need to be replaced. Like all cold saw blades, high speed steel blades need to be kept cooled and lubricated.
Tungsten Carbide Tipped Blade
Strange as it might sound, the tungsten carbide tipped blade is meant to cut at a much faster rate than the high speed steel blade. This is because of the tungsten carbide tips on the teeth of the blade. The tips are ground onto a blade that is made of chrome vanadium steel alloy and has been specially heat treated so it’s extremely resistant to wear. Although tungsten carbide tipped blades were originally just used on non-ferrous metals, their usage has widened to include ferrous metals in recent times.
The big problem with tungsten carbide tipped blades is that when cutting, the saw and material need to be vibration-free. Vibrations can damage the teeth of the saw blade. This means they’re extremely susceptible to shocks. If you can avoid these conditions, tungsten carbide tipped blades for the cold saw have a very long life and can be resharpened several times.