Understanding Circular Saw Blades

26 Jun.,2023

 

Understanding and Choosing a Circular Saw Blade


As part of White Cap’s series of helpful articles created exclusively for our customers, this article covers Circular Saw Blades for wood, sheet goods, and metal. 

Why Does Selecting the Right Blade Matter?

Selecting the right saw blade allows you to produce a better product, deliver it more quickly, as well as save money in the long run.

Selecting the right saw blade allows you to produce a better product, deliver it more quickly, as well as save money in the long run.

High-quality blades

offer longer life spans, more heat resistance, and more durability than budget blades. High-quality blades will also yield superior results and save money in the long run. Let’s look at three key areas where blade selection matters most.

Safety
While premium blades may cost slightly more up front, the expense pays off in added safety.   

Cut Quality
All blades cut, but there’s a big difference between the final cuts made by high-quality blades vs a cheaper blade. Cheaper blades eat through more material, generating more waste. They need sharpening more often which means more labor spent changing blades more frequently, as well as the added cost of sharpening or replacing more often than premium blades.

Longer Blade Life
You get what you pay for. With premium quality saw blades, you’ll save money due to the exceptional construction and better grade of materials used in constructing the blade. These and several other influencing factors we discuss further in this article, all add up to a stronger, longer blade life.

Always buy the best you can afford. When you buy a premium tool or blades, you’re making an investment in the quality of the product that you’ll produce and an investment in your professional reputation. And because a cheaper blade is usually made by less expensive manufacturing process with standard materials, you’ll achieve less precise cuts, resulting in an inferior product. When you invest in premium tools, you achieve high-quality results.

The saw blade is the most important consideration in the tool/accessory relationship.


Blade Anatomy & Construction

 
Saw Blade Essentials
Most saw blades are designed to do their best work in a certain type of cutting operation. There are blades designed for ripping lumber, crosscutting lumber, cutting veneered plywood and panels, cutting laminates and plastics, cutting melamine, and cutting aluminum. There are also general purpose and combination blades designed to work well in two or more types of cut. What a blade does best is determined by the number of teeth, tooth configuration, and the angle of the tooth (hook angle). 

Let’s look at the main influencers for buying a circular saw blade: 

  • Diameter - Considered as a blade’s size. All circular saw blades, and even saws, are identified by this measurement. Diameter is the length between the tips of two teeth on opposite sides of each other. As the diameter increases, so does the need for a high-quality plate. 
  • Arbor - Is the saw shaft where a circular saw blade is mounted. The arbor provides power from the motor to the blade. The blade’s center that mounts onto a saw’s arbor is called the bore, or arbor hole. Available in a variety of sizes, the larger the blade diameter, the larger the arbor hole. Always make sure the arbor hole snugly fits the saw’s arbor to avoid a wobbly blade and an extremely dangerous situation.

  • Tooth grind - This is sometimes called the “bevel”. This is the blade’s specific tooth shape. The tooth shape is specifically optimized for the material it will be cutting. The most common tooth grinds are:
 

o   ATB (Alternate Top Bevel)

o   TCG (Triple-Chip Grind)

o   FTG (Flat-Top Grind).


 
These are discussed in more detail later in

 
    • Kerf and Blade Width - Kerf is the thickness of a cut that a blade makes, usually 3.175mm wide. Kerf width describes the blade thickness. The kerf width, the teeth’s vertical angle, and blade wobble determine a blade’s kerf. For smooth cuts when working with furniture, cabinets, and other fine woodworking applications, use thin kerf blades with many teeth with little-to-no angle.

      o  Thin kerf blades (1.5mm or thicker) - The thinner the kerf (cutting width) on a blade, the less material waste. Use this blade with expensive hardwoods, hardwood plywood, dimensional, or engineered lumber for precise cuts, better finish, and save up to 30% of materials compared to full kerf blades. While some thinner blades may overheat on rip cuts and long cuts, kickback, and offer little side clearance, manufacturers have created vibration-dampening systems, and thin kerf blades that rival industrial-quality full kerf blades. White Cap has a large selection of thin kerf blades for rip cutting, crosscutting, or combination.


      o  Ultra-thin Kerf (1.35mm or less; same thickness as a dime) - Useful for applications that require thin-strip ripping. These types of blades produce more precise cuts and waste less material.

      o  Here are a few more benefits of using ultra-thin kerf blades:

1.  Faster cut

2.  Less amp draw / Longer run time

3.  Produces less sawdust

4.  Lower resistance means it makes a lower powered saw more efficient.

Most saw blades are designed to do their best work in a certain type of cutting operation. There are blades designed for ripping lumber, crosscutting lumber, cutting veneered plywood and panels, cutting laminates and plastics, cutting melamine, and cutting aluminum. There are also general purpose and combination blades designed to work well in two or more types of cut. What a blade does best is determined by the number of teeth, tooth configuration, and the angle of the tooth (hook angle).Let’s look at the main influencers for buying a circular saw blade:These are discussed in more detail later in

Tooth Geometry


RPM (Revolutions Per Minute)
– Listed on all blade packaging, this important safety information is to ensure that your saw’s maximum RPM is less than your blade’s maximum RPM.

It's important to look at the RMP rating of both the tool and the blade, and match them accordingly. This is particularly true when it comes to steel cutting blades. It’s critical to run large diameter steel cutting blades (8” and greater) on low-RPM, high-torque, specialty metal-cutting saws.

It should be noted that the RPM of a circular saw does NOT indicate its cutting speed. That’s determined by the number of teeth and the diameter size of the blade. A 10” blade is going to cut faster than a 7 ¼” blade because it’s bigger and can eat through more material quicker than a smaller blade even if both blades are revolving at the same RPM.




How to Select the Right Blade

Choosing the right blade depends upon what kind of material will be cut and what tool will be used to cut the materials. Here are some recommended blades for some common applications. 

For use with table saws (standard 10” or 12” blade) and portable circular saws (6 ½” or 7 ¼” blade):

  • Natural wood - use a 24T (teeth) to 30T premium quality blade for ripping.

  • Plywood - use 40T to 80T premium quality general purpose blade for cutting or cross-cutting

  • MDF – (Medium-Density Fiberboard – and similar man-made materials) - go with a 50T to 80T. 60T and higher produces cleaner precise cuts in dense materials.

  • Plastic Laminate - 80T cross-cut blade, but 60T composite blade for thinner materials.

Choosing the right blade depends upon what kind of material will be cut and what tool will be used to cut the materials. Here are some recommended blades for some common applications.For use with(standard 10” or 12” blade) and(6 ½” or 7 ¼” blade):

When using a miter/chop saw and the standard blade 8”, 10”, or 12” diameters:

  • 2x4 lumber - use 24T blade

  • 10” general purpose - use a 50T/60T blade

  • Cleanest trim cuts - 80T blade is recommended.
 
Metal - A carbide-tipped abrasive cutoff wheel may be a good choice. 

 

Saw Blade Materials

The plate quality of circular saw blades is important, especially when purchasing larger diameter blades. When constructed from a high-quality material, a blade will have a longer life span, be wobble-free, and run true, producing a good finish and cleaner cuts. 

HSS (High speed steel): Though rapidly becoming obsolete, HSS blades are made of ferrous metal with chrome-vanadium or cobalt alloy for longer use and less warping. Use to cut thin-walled steel tubes and profiles, pipes, sheets, plates, non-alloy tool steel, extrusions, structural and solid sections.   

Carbide Teeth: Carbide is an extremely hard but somewhat brittle compound metal created by combining tungsten carbide particles with specific amounts of cobalt. Many saw blades today have teeth that are enhanced with carbide tips welded directly onto the saw tooth. This creates an incredibly hard-cutting tooth that does not wear down quickly, is impact resistant, withstands high heat, cuts clean, and is cost effective with a longer life span than non-carbide-teeth blades.

Cermet (Ceramic and Metallic) Teeth: Lasts up to 40X longer than standard carbide metal cutting blades due to their high-heat tolerance, increased hardness, and superior wear. The Triple Chip Tooth design provides less sparks, burr-free finishes that require no-rework, and longer cutting life.

Standard vs Premium Blades



This table shows several of the advantages of premium blades over standard blades.

- A carbide-tipped abrasive cutoff wheel may be a good choice.The plate quality of circular saw blades is important, especially when purchasing larger diameter blades. When constructed from a high-quality material, a blade will have a longer life span, be wobble-free, and run true, producing a good finish and cleaner cuts.Though rapidly becoming obsolete, HSS blades are made of ferrous metal with chrome-vanadium or cobalt alloy for longer use and less warping. Use to cut thin-walled steel tubes and profiles, pipes, sheets, plates, non-alloy tool steel, extrusions, structural and solid sections.Carbide is an extremely hard but somewhat brittle compound metal created by combining tungsten carbide particles with specific amounts of cobalt. Many saw blades today have teeth that are enhanced with carbide tips welded directly onto the saw tooth. This creates an incredibly hard-cutting tooth that does not wear down quickly, is impact resistant, withstands high heat, cuts clean, and is cost effective with a longer life span than non-carbide-teeth blades.Lasts up to 40X longer than standard carbide metal cutting blades due to their high-heat tolerance, increased hardness, and superior wear. The Triple Chip Tooth design provides less sparks, burr-free finishes that require no-rework, and longer cutting life.This table shows several of the advantages of premium blades over standard blades.

Wood Cutting:

  • Material: Cutting solid and hard woods, as well as wood-based manmade materials such as plywood, MDF, and Oriented Strand Board (OSB).
  • Application:

    o  Ripping – cutting in the direction of the grain

    o  Crosscutting – cutting across the grain of the wood

    o  Sizing -  cutting sheet goods

  • Machines:

    o  Table saws, miter saws, and handheld circular saws

    o  Make sure the machine’s RPMs are less than the max RPMs advised for the blade.

  • Teeth Count:

    o  Low teeth count for ripping. (Ex: 10” diameter blade with 24 teeth.)

    o  Mid- range teeth count for general purpose, crosscutting, and ripping. (Ex: 10” diameter blade with 40 teeth.)

    o  High teeth count for crosscutting or cutting sheet goods. (Ex: 10” diameter blade with 80 teeth.)

  • Teeth Geometry:

    o  Alternate Top Bevel (ATB):  Alternating beveled teeth score the material for a clean cut.

    o  Hi-Alternate Top Bevel (Hi-ATB): An exaggerated top bevel enhances the scoring action of the blade for fine finish cross cuts or cuts in sheet goods.

  • Carbide Teeth: 

    o  Quality carbide is a game changer. Inferior carbide will wear quickly – the geometry of the teeth will degrade and so will the blade’s cutting ability.

    o  High-quality micrograin carbide is intentionally designed for controlled wear and long life.


Steel Cutting:  

  • Material:  Cutting mild steels and stainless steels*

  • Machines:

    o  Steel cutting blades 8” diameter or larger must be used in low RPM stationary or handheld dry cut saws (not a chop saw).

    o  Steel cutting blades smaller than 8” diameter can be used in specialty metal cutting saws (for optimal performance) or in traditional handheld framing circular saws.

  • Teeth Count:

    o  Higher tooth counts for thicker materials

    o  Lower tooth counts for thinner

  • Teeth Geometry:  TCG (Triple Chip Grind)

  • Carbide Teeth: For cutting mild steels only. Not optimal for stainless steels.

  • Cermet Teeth: For cutting both mild and stainless steels.

*Steel cutting blades that have carbide teeth generally shouldn’t be used for cutting stainless.  Blades that cut stainless should have cermet teeth.


Note: It’s extremely important to wear safety equipment such as protective eye goggles, cut-resistant work gloves, plus hearing protection.

 

Aluminum Cutting:

  • Material: Cutting blades for aluminum, copper, and brass, as well as for plastics (acrylic, Lexan, polycarbonate, etc.)

  • Machines:

o  Aluminum cutting blades can be used on traditional wood cutting saws.

o  Table saws, miter saws, and handheld circular saws. Do not use aluminum cutting blades on sliding compound miter saws.

o  Make sure the machine’s RPMs are less than the max RPMs advised for the blade.

 

  • Teeth Count: 

o  Higher teeth count for thick-walled materials.

o  Use lower teeth count for thin-walled materials.

 

  • Teeth Geometry:

    o  Triple Chip Grind (TCG): This is a durable two-tooth sequence. The first tooth, with chamfered corners, hogs out the material. The second tooth follows to finish the cut.

  • Carbide Teeth:

    o  Quality carbide is a difference maker. Inferior carbide will wear quickly – the geometry of the teeth will degrade and so will the blade’s cutting ability.

    o  High-quality micrograin carbide is intentionally designed for controlled wear and long life.

  • Cutting Lubricants:

    o  While manufacturers like Diablo have designed their aluminum cutting blades to cut dry (without lubricant), the use of cutting lubricants can dramatically increase the life of a blade.



Specialty Cutting:

  • Machines:

    o  Specialty blades can typically be used on traditional wood cutting saws: Table saws, miter saws, and handheld circular saws.

    o  Make sure the machine’s RPMs are less than the max RPMs advised for the blade.

  • Application: There are a wide variety of blades that are designed for niche materials that are difficult to cut with wood cutting or metal cutting blades.

Examples of these blades are:

  • Polycrystalline Diamond (PCD) blades for cutting cement fiberboard (Hardie)
  • Polycrystalline Diamond (PCD) blades for cutting laminate or pre-finished flooring (Pergo, for example)
  • Composite decking blades with a modified triple chip grind (TCG)
  • Wood and metal dual use blades – a single blade that can cut both mild steels and wood.

Teeth Geometry

*Steel cutting blades that have carbide teeth generally shouldn’t be used for cutting stainless. Blades that cut stainless should have cermet teeth.Note: It’s extremely important to wear safety equipment such as protective eye goggles, cut-resistant work gloves, plus hearing protection.

Teeth geometry is the particular grind applied to the blade's teeth which determines how they cut. Here are the most common grinds.


Alternate Top Bevel (ATB): Cutting like knives, teeth alternate between a right- and left-hand bevel, making a cleaner cut than flat-top teeth. Produces a smoother crosscut on natural woods and veneered plywood. For crosscutting, cut-off, trimming, and ripping. 


Triple-Chip Grind (TCG): With beveled corners, teeth alternate between a flat “raking” tooth and a higher “trapeze” tooth. Very durable. Good for working with hard, abrasive materials like non-ferrous metals, hardwoods, laminates, MDF, and plastics.

  
Flat-Top Grind (FTG): Use mainly for ripping when fast feed rate is important to prevent overheating. Best for ripping hard and soft woods.



Hook Angle

Teeth have steeply beveled angles which affect cut and feed rate. High/positive angle means the teeth lean forward, cutting very aggressively with fast feed rate. Low/negative angle teeth lean back, opposite direction of the blade rotation. Slow feed rate, and inhibits blade's tendency to "climb" the material being cut. Good for cutting melamine and hardwood plywood.

 

Number of Teeth

It’s a common misconception that the number of teeth on the blade determines the quality of the blade. The reality is that the number of teeth affects speed, type, and finish. Blades with fewer teeth cut faster, but with a rougher finish than blades with more teeth which cut slower and much smoother.  

 
Ripping blades have the least amount of teeth; panel blades have the most. Crosscut blades, combination and general-purpose blades fall somewhere in-between.


Expansion Slots

An expansion slot is an innovative curved laser-cut or stamped vent on the blade plate designed to keep the blade from warping when overheated.


As they cut, a blade’s teeth are cooled by moving air. However, the blade plate gets extremely hot from the cutting friction. With nowhere to go, the ever-increasing heat expands sideways unevenly thorough the plate, warping and destroying the blade. Without expansion slots a blade will cup when it overheats.


Expansion slots allow the blade to expel its heat, preventing warping and reducing vibration. On premium blades, the expansion slots will be laser cut and connected to rounded holes near the arbor.


Contactor blades offer stamped expansion slots.


 

Checking Blade Quality & Condition

To create a quality product, you need to have high-quality tools. Besides your saws, circular saw blades are your most important tool accessories. It’s important to periodically check them to make sure they’re in perfect condition, need sharpening, or replacing.


Inspecting your blade's quality

  • Check for pitch. Poor cutting can be a result of a dirty blade.
  • Look for signs of wear or damage. Any missing, chipped, broken, or worn-down teeth?
  • Check the wear line of carbide edges.
  • How does the blade cut? Sharp? Dull? Wobbly? It may be time to sharpen. A good quality blade can be sharpened many times.
  • If you frequently cut metal or hardwoods, consider replacing.


Factors that influence blade quality

  • The type of work you do
  • The quality of your tools
  • How often you use your blades
  • How often you clean and maintain your tools
  • Are your blades properly stored?
  • How often are they sharpened and cleaned?


Symptoms of a dull blade that needs sharpening:

  • Increased resistance to feed
  • Burning
  • Increased noise
  • Chips or splinters
  • Increased motor load
  • Rounded teeth

Storage

When creating storage, consider: Convenience, function, and protection. Let them be your guide in creating storage. Whatever style storage you choose, always keep blades away from moisture and humidity. There are so many storage options available; you’re only limited by your creativity. 

  • Hang blades individually on the wall with hooks.

  • Magazine-style storage rack: Basically, a wooden or metal frame mounted to the wall with slanted slots for blades. Great for storing high-end saw blades.

  • Slide-out CD-style box: Keeps blades safely concealed, organized, and accessible without them banging against each other.

  • Knife block: Similar to your kitchen block, but sturdy enough and with large slots to hold heavy blades.

  • Pull-out drawers: Build one into your saw table. Takes up minimal space and provides easy access.

  • In between jobs, rest blades on plastic or plywood. Never place your blades on cement or steel surfaces. It can dull the blade.

  • When storing, try to keep blades from rubbing against each other.



Circular Saw Blade Safety Best Practices 

 

  • Always follow OSHA manufacturers’ guidelines.

  • Wear regulated safety eye protection, dust mask, and ear protection.

  • Avoid wearing loose clothing, dangling jewelry, tool belt, nor long hair that can be pulled unexpectedly into the saw.

  • Do not wear gloves while operating a table saw.

  • Check cutting surface for dangerous stray objects, nails, and screws.

  • Floor area around a table saw should be free of items that could cause you to trip or fall.

  • Stand comfortably, with your feet far enough apart for good balance. You should be able to stop cutting quickly if needed. This is important if cutting stock long enough to require walking several steps towards the saw to keep the feed going.

  • Stand to the side of a table saw when cutting to avoid kickbacks.

  • Use both hands to operate a circular saw to maintain control. Clamp down work pieces so they don’t move while being cut.

  • Always disconnect a saw’s power plug before changing a blade, performing any maintenance, or adjusting. Always remove batteries from cordless saws.

  • Before disconnecting a saw from an outlet, always make sure that the blade has completely stopped turning.

  • After making adjustments or blade changes, spin the blade before plugging back into an outlet.

  • Before cutting, check your blade for sharpness, and make sure it is clean and free from build-up and debris. Make sure the arbor nut is not overly tight.

  • Do not alter the lower guard by tying or wedging it open. Leave the guard to pivot so that the blade is always safe.


Check out our huge in-stock selection of high-quality circular saw blades and power tool accessories.We make ordering easy: Order online (link), call 800-944-8322, or visit your favorite White Cap location.

Want more information on K-Turbo Saw Blade, Segmented Saw Blade for Stone? Click the link below to contact us.

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