Choosing a Steel Band Saw Blade
A metal cutting band saw blade is a critical piece of equipment for any fabrication shop. Choosing the right blade, using it correctly, and keeping it in good condition will help ensure maximum productivity.
The ideal tpi depends on material thickness and diameter for tube and profiles, and on machinability for solid materials. Generally, higher feed rates reduce blade life.
Tooth Set
The way the teeth are set in a band saw blade impacts cutting speed, raking effect (for clearing the cut), and overall smoothness. The tooth set is also a factor in determining blade life.
Tooth set is a complex puzzle of factors that are determined by many other blade characteristics, such as tooth pitch, shape, and rake angle. The final answer to how well a metal band saw blade performs is a combination of these factors that is unique to each job.
Some common tooth sets used for metal cutting are a regular raker set with a straight sequence, a skip set that has an open space between each teeth for non-ferrous cutting, or a wavy set, which offers a greater range of applications than the raker set. Some blades also have a special combination tooth set that is best for certain materials.
The most important determinant of the life of a metal band saw blade is operator care, which includes maintaining proper feed pressure and using an appropriate blade guide. Using excessive force on the workpiece or blade will shorten the life of a blade and lead to premature wear. The operator should also keep the blade sharp by regularly cleaning the blade and the machine to remove debris from the cutting surface. In addition, a properly run break-in procedure is essential.
Tooth Material
The material used to make the tooth set is a crucial factor that influences how well and quickly a blade cuts. There are a few different choices, including bimetal and carbide-tipped blades. Carbide-tipped blades tend to be a bit more expensive but are better suited for tough jobs like cutting hard metals, abrasive wood materials, and nonferrous metals.
Band saw blade manufacturers have developed a variety of different tooth set designs to provide effective cutting solutions for a wide range Steel band saw blade of applications. A standard set has a series of teeth that are alternately bent to the left and right, making it ideal for general purpose cutting. Other choices include wavy and alternative sets, which feature groups of bent teeth that are positioned further apart than a standard set.
Structural shapes often pinch band saw blades, which can cause premature wear and a poor cut. A wider tooth set minimizes this problem by creating a larger kerf and decreasing the amount of pressure exerted on the blade. Another way to reduce the likelihood of pinching is to use a blade with a variable pitch. Variable pitch teeth have varying spacing, gullet depth, and rake angle, which can significantly decrease harmonic vibrations. This can result in reduced noise levels and vibrations, and a better overall cut.
Tooth Geometry
There’s a lot to consider when selecting band saw blades for structural cutting. Finding the right combination of tooth pitch, shape, rake angle and material will help you get the most performance out of your blades. This involves knowing what each blade has to offer and understanding when it’s best for the specific job you have in mind.
For example, a bimetal blade has an alloy steel body that provides flexibility with a fused layer of wear-resistant high-speed steel (HSS) comprising the teeth. This unique geometry helps Tinplate Sheet Manufacturer limit damage from interrupted cuts in structural shapes, where the stresses are constantly changing.
Another important factor is the size and shape of the blade’s gullet. The larger the gullet, the more the blade can handle while reducing noise, vibration and burr. The gullet should also be smooth, as sharp corners concentrate stress and can cause the blade to break.
Depending on the application, the tooth shape can be ground or carbide tipped. A wavy set uses groups of teeth that are alternately angled right and left to reduce noise, vibration and burr on thinner cuts like those made in tubes or metal sections. A carbide-tipped blade has pocketed teeth formed into the back of the body that are welded with a harder, more durable tip material like Stellite, diamond or ceramic.
Tooth Finish
A quality band saw blade will have a fine tooth finish that produces high-quality cuts with little heat. This helps reduce the risk of premature failure caused by excessive heat, as well as extends blade life and increases cutting efficiency.
A fine tooth finish also allows for greater coolant flow through the teeth, lubricating and cooling them. This enables the blade to cut at higher speeds with less pressure, which is an important factor for reducing noise and vibration during sawing.
Oftentimes, a fine tooth finish can improve the appearance of the finished product by leaving it with a smoother surface. However, if the tooth finish is too fine, it can cause issues like abrasiveness and excessive heat during cutting.
For metal fabrication shops, bi-metal band saw blades are the preferred choice because they’re able to cut both solid and ferrous materials while remaining tough enough for interrupted cuts, such as those made when cutting structural shapes. The oversized blade width and specific tooth geometry limit damage that occurs during these cuts. Moreover, the grooved tooth geometry of these blades results in dual, or split chips that are small and easy to evacuate. As a result, they don’t cling to the teeth and wear them down as fast as they do in structural-type blades. This feature makes them a great choice for a variety of industries and applications, including steel service centers, small to large manufacturers, fabricators, maintenance or job shops, as well as tool and die shops.