Circular Saw Blades
on June 13 2013
Circular saw blades are round-shaped cutting implements designed for use with miter saws, table saws, radial arm saws, cut-off saws and standard circular saws. Many circular blades can be used interchangeably between devices. Using the right blade for each job improves performance and efficiency.
Manufacturers often label their blades with information about the type of saws, materials and/or applications each one is designed for, giving you a variety of options to consider. Before you learn about your choices, use the following questions to start thinking about your needs:
• Which saws do you use that require a circular saw blade?
• What applications/materials do you use your saw(s) for?
• Do you make slow, precise cuts or fast, rough cuts?
• What price range are you looking to stay within?
Teeth, Dimensions and Construction
Circular saw blades vary widely in price. More expensive blades usually have features that extend the longevity of the blade while enhancing performance. Inexpensive blades may dull quickly or produce rougher cuts, so make sure you weigh the benefits of each blade in addition to the initial cost. Dimensions:
There are three dimensions to keep in mind when you are shopping for circular saw blades - diameter, arbor size and kerf. The first two dimensions, diameter and arbor size are determined by the saw. Blade diameters start at 3-3/8-inches, but the most common diameters are 7-1/4-inches for circular saws, 10-inches for table saws and 10-inches and 12-inches for miter saws.
Arbor sizes range from ½-inch to 1-inch. Check your saw or owner's manual to see what size blades you need. Kerf, which tells you how thick or thin a given blade is, gives you a range of options. Thick-kerf blades last longer and can be resharpened, so they tend to be more expensive.
• Thin-kerf blades are sharper and faster when new but can dull quickly
• Thin-kerf blades remove less material from the work piece during cuts
• Thick-kerf blades hold up to nails better and resist wobble
In general, blades with more teeth yield a cleaner cut and blades with fewer teeth deliver faster cuts with rougher edges. The number of teeth should always be considered in relation to the diameter of the blade. Fewer teeth create larger gullets, removing material quickly and reducing clogging, which is important for lengthwise cuts.
A small gullet size is best for crosscuts. Tooth grind, shape and hook are also very important in determining the longevity of the blade, quality of cut and recommended applications.
• Fine-cut blades with a high number of teeth are used for high-quality cuts and thinner materials
• Tooth hook refers to the attack angle of the tooth (positive, neutral or negative)
• An aggressive positive hook produces faster cuts but tends to increase tear out Construction:
Circular saw blades are usually constructed of steel or carbide-tipped steel. Steel blades are inexpensive but the teeth can dull quickly, so they are often preferred for more occasional use. Carbide-tipped blades, on the other hand are extremely durable, with their long life often compensating for the higher price tag. For masonry and metal applications, you will need an abrasive wheel or diamond blade.
• Dry-cut diamond blades cut faster than abrasive wheels without heating up the material
• Carbide-tipped blades require less frequent sharpening, reducing downtime
• Carbide-tipped blades last up to ten times longer than steel blade Applications:
Manufacturers often tell you which saws, materials and/or cuts each of their blades is designed for, eliminating guesswork. The chart below provides a general overview of choices, but most manufacturers offer blades designed for specific materials, such as laminate, aluminum, plywood and many others. The recommended application(s) are usually printed right on the blade for easy identification even after the packaging has been removed.
Specialized blades deliver better results for the recommended use than all-purpose blades, but they will require you to change blades more often. Combination blades are popular among users with diverse needs because they minimize downtime due to blade changes, but the resulting crosscuts and rips can be of a lower quality than if specialized blades were used for each cut.
||Crosscutting wood (cutting across the grain)
||Ripping wood (cutting with the grain); should not be used on plywood
||All-purpose cutting in wood
|Fine-tooth finish blade (e.g., 7-1/4-inches blade with more than 40 teeth or 10-inches blade with more than 60 teeth)
||Very smooth cuts
|Finish or paneling blade
||Paneling, veneer, plywood, laminates, plastics and other light-gauge materials
||Wood with nails or other foreign bodies
||Metal sheets and pipe
||Masonry and metal
||Masonry and tile
|Dado-cut blades (radial-arm and table saws only)
||Dado and rabbet cuts in wood (grove cuts)
Slots in the blade prevent warping by allowing the metal to expand and cool when it gets hot. Laser-Cut Features:
Laser-cutting delivers a more precise result than stamping, enhancing accuracy and performance. Look for laser-cut bodies, arbors and expansion slots on saw blades for higher quality cuts. Coating:
Some blades are coated to prevent corrosion, friction and/or gum up, extending blade life.