June 23, 2018

Table Saw Blades

Freud D1050X Diablo 10-Inch 50-tooth ATB Combination Saw BladeOnce you’ve bought your new table saw, you’re probably not thinking about going out and buying a new blade to replace the one that came with your saw.

However, the type and quality of the blade you use in your table saw has a huge impact on the quality of the cut and how much work you will need to do finishing the sawn edge of the workpiece.

A good blade on a poor saw will make better, cleaner cuts than a cheap blade on the most expensive saw, and a lot of woodworkers would argue that the most important part of any saw (not just a table saw) is the blade.

The most common sawblades are designed for ripping and crosscutting solid wood, although there are also a number of specialty blades for cutting man-made sheet stock such as MDF and plywood and plastic coated materials such as melamine.

There are three main types of table saw blade depending on what you use them for – ripping, crosscutting or combination blades, which can be used for both. These days the majority of blades are carbide or titanium carbide tipped which dramatically increases the life of the blade.

What to look for in a Table Saw Blade

The main factors affecting the quality of cut are

  • The number of teeth
  • The tooth pattern
  • Blade Flatness & Design
  • Carbide tips

Ripping, Crosscutting and Combination Saw Blades

Number of Teeth

The first difference is the number of teeth – rip blades have fewer teeth than crosscutting (also called cut-off or finish) blades and combination blades are somewhere in the middle. A typical 10-inch rip blade like the Freud LU87R010 10-Inch 24-Tooth FTG Thin Kerf Ripping Saw Blade will have 24 teeth, compared to a typical 10-inch finish blade like the Freud D1080X Diablo 10-Inch 80-tooth ATB Finish Saw Blade which has 80 teeth.

In any normal woodworking session you will want to make both rip and crosscuts and it’s a chore to have to change back and forth between blades – hence the popularity of combination blades which can be used for both types of cut. A typical 10-inch combination blade like the Freud D1050X Diablo 10-Inch 50-tooth ATB Combination Saw Blade has got 50 teeth.

A combination blade makes good sense for many woodworkers. Although a combination blade, also called a general-purpose blade, might not rip as well as a rip blade or crosscut as well as a crosscut blade, it can come pretty close.

These blades may be a compromise between dedicated rip and crosscut blades but they can still produce an excellent quality of cut. As you would expect, the more expensive blades generally produce a better finish, but, since you only have to buy one blade for both jobs, you can afford to buy the best quality blades.

Saw Blade Tooth Patterns

The second difference between the different types of saw blade is in the design of the teeth. There are a number of different types  designed for different applications:

Saw Blade GeometryATB (Alternate Top Bevel) Saw Blades
ATB teeth are used on crosscutting and combination blades – they have alternating teeth beveled in opposite directions which, when combined with the higher number of teeth on a cut-off or combination blade, results in an extremely clean cut when crosscutting. ATB blades are the most common type of blade and there are a number of specialist variations:

ATB+R (ATB with Raker) Saw Blades
For faster rip cuts, a flat-topped raker tooth can be added between sets of beveled teeth. The most common design has four ATB teeth followed by one flat-top raker tooth for cleaning out the cut. The result is a genuine multi-purpose blade which is effective for rips and crosscuts in solid wood as well as sheet stock.

H-ATB (High Alternating Top Bevel) Saw Blades
With its paper-thin veneer, plywood can be a bit of a challenge to cut without chipping or splintering, and plastic laminates are also difficult to cut because the brittle plastic veneer tends to chip. H-ATB blades are designed to combat this with a high (or steep) top bevel and an unaggressive rake which results in very pointed teeth with a very sharp edge. This means you get a very clean cut without chipping, but the teeth dull quite quickly.

TCG (Triple Chip Grind) Saw Blades
A triple chip grind blade is designed for chip-free cuts in hard wood, plastics and plastic laminated to wood, such as melamine. With a TCG configuration the teeth alternate between a flat raking tooth and a higher “trapeze” tooth. Because it doesn’t have sharp points like ATB blades, a TCG blade will last much longer and handle the high impact of cutting hard stock.

FTG (Flat Top Grind) Saw Blades
FTG teeth are exactly as you would expect – they have a flat top – and are designed to cut with the grain and are only used on rip blades. Since wood is much less likely to chip and splinter when it is being cut in the direction of the grain, the focus of a rip blade is to quickly and efficiently remove material. The flat top tooth is the most efficient design for cutting and raking material out of the cut. However, even for rip blades they are not as common as the were as a lot of manufacturers now use ATB or TCG teeth with a positive rake on their rip blades.

Rake (or Hook) Angles
This is the amount that a saw blade tooth either tips toward or away from the direction of the blade rotation. A zero degree hook angle means that the face of the teeth are in line with the exact center of the blade. A positive rake is more aggressive and is used for ripping whereas at the other end of the scale a negative rake is used for extra-fine crosscutting in veneered plywood or melamine. General purpose combination blades will tend to have a positive rake that is not as aggressive as the rake on a rip blade.

Blade Flatness & Design

The basic rule is that the flatter the blade, the better the cut, which makes sense, and generally thicker blades are flatter. Standard saw blades produce a 1/8- inch wide kerf, and you can also buy narrow kerf blades that have a slightly thinner plate so they take less power to operate and consume less material, but they are not as stiff as a standard blade. Everything is a trade-off.

Manufacturers use a variety of plate designs to improve overall performance such as expansion slots allowing the blade to expand and contract from heat preventing warpage and heat build-up, copper plugs and anti-vibration slots that reduce chatter for a cleaner finish, longer blade life, and reduced noise and vibration during operation, plus various coatings that reduce friction and eliminate heat buildup as well as reduce gumming, rusting, and corrosion – gummy pitch or rust buildup causes extra drag on the motor of your saw, so less buildup means longer tool life and longer blade life.

 Carbide Tips

Carbide tips maintain blade sharpness and the two key factors are the quality of the carbide and how much of it is there. Obviously, better-quality carbide is more durable, and there should be enough of it to allow for a number of sharpenings before the blade must be scrapped.

Again, all the top manufacturers use a number of proprietary solutions such as Freud’s “shock-resistant TiCo Hi-Density Carbide formula” or Forrest who use “superior C-4 carbide teeth hand-brazed to the plate”. All the manufacturers have their own designs and price is as good an indicator as any – the more expensive the saw blade, the better the quality.