Zero Clearance Table Saw Insert
Zero clearance table saw inserts (also called throat plates) are an inexpensive upgrade to any table saw and offer several benefits, including:
- Reduced risk of blow out
- Improved cut quality
- More control over the piece as it moves through the saw
- Prevents small pieces from falling through the throat
One somewhat significant drawback is that you’ll likely see a bit more sawdust kicked up because of using a zero clearance insert. Sawdust normally exits below the standard plate that’s included with the saw. Either the saw or a dust collection system creates a downdraft that helps to pull the sawdust down into a collection area (if you saw has one).
When using a zero clearance insert, there is no airway for a downdraft to occur.
Zero Clearance Dado Inserts
Zero clearance inserts for dado blades are also available and can be custom made. Not all table saws can run dado blades, so check with your owner’s manual before looking for the insert. For example, the SawStop compact model cannot run dado blades and thus a dado blade insert for that model does not exist.
How to install a zero clearance insert
Unplug the table saw and remove the factory throat plate
Safety first, unplug the saw from the while, turn off any breakers connected to the saw. Turn the switch on to verify there is no power going to the motor. Remove the factory throat plate and clean out any saw dust or other debris around the blade.
Raise the blade and remove the riving knife
Crank the saw blade up enough so that you can remove the riving knife. Different saws will have different mechanisms for removing the riving knife. Refer to your owner's manual for how to remove it properly. For the DeWalt DWE7491RS shown below, there is a mechanism on the left-hand side of the table that has to be pulled to release the riving knife.
Fully lower the blade after removing the riving knife.
Adjust the zero clearance insert for a secure fit
In the photos below, we are using Leecraft’s zero clearance table saw insert, which includes 5 adjustment screws. 4 screws are on the top and there is one screw on the right-hand side.
Again, check to ensure there is no dust or debris around where the insert will fit. Adjust the screws so there is no left or right play. Then adjust the 4 top screws so that the insert sits a hair below the surface of the table saw.
Here I am using a machinist’s angle to check for flatness. You can see a very small gap between the table saw’s surface and the zero clearance insert.
The gap between the angle block and zero clearance insert shown here is excessive.
The gap between the angle block and zero clearance insert shown here is acceptable.
Clamp a 2x4 on top of the zero clearance insert
After the insert is just below flush with the rest of the table saw surface, clamp a 2x4 across the top of the insert with it extending across the surface of the table saw. Use a clamp on both ends of the saw as we’ll be raising the blade through this piece of wood.
Make sure the piece of wood is aligned so that the blade will be raised through the center of it and there is no risk of the stud shifting during the cut.
Plug in the saw, turn it on, and slowly raise the blade
Put on ear and eye protection.
Plug the saw into the wall outlet and power it on. Slowly raise the blade until it reaches its maximum height. The blade will cut through the insert and the 2x4 as it’s raised up. Once the blade has reached its maximum height, turn off the saw and again unplug it from the power source.
Remove the clamps and 2x4 and check the cut made in the insert. Remove the insert and place it upside down on the surface of the table saw.
Re-install the riving knife
Re-install the riving knife behind the blade.
The next steps will use the table saw to make an insert for the riving knife. You may also use a jigsaw to make the rest of the cut. The width of the cut for the riving knife doesn’t have to be perfect.
Lower the blade to a tooth higher than the depth of the insert
Using the upside down insert as a reference, lower the blade so that its height is roughly 1 full tooth higher than the depth of the insert.
We’ll be making a partial through cut to account for the riving knife.
Adjust the fence to align with the insert
Set the upside down insert on the saw blade so that the blade comes through the hole we just cut into it. Adjust the fence so that it is flush with the insert.
Take the insert off of the blade and then make a partial through cut. Turn the saw off after you have made a partial through-cut.
Apply Wax
As a finishing touch, apply a thin layer or two of paste wax.
If installing on a DeWalt DWE7491RS, remember to remove the insert before transporting. There is no locking mechanism on the new insert.
Where to buy a zero clearance table saw insert?
We’ve listed links below to some of the more common table saw models on the market and recommended zero clearance inserts. You’ll notice in a lot of the product listing images there is not an opening for the saw blade to come through.
That’s because you create the opening when you set the insert into the table saw.
When you set the insert into the table saw throat, you'll anchor the insert down with a piece of wood or duct tape and then, with the saw running, raise the blade through the insert.
Zero Clearance Insert for DeWalt Table Saw
If you picked up your DeWalt table saw from Home Depot or Lowe’s, odds are it’s one of the model numbers below. To locate your model number, check the front of the saw for a label that shows power input and other details. The model number for DeWalt power tools will always start with a ‘D’.
Different model DeWalt table saws have different size inserts, so be sure your model is compatible with the inserts below.
DWE7485 | 8 ¼” Compact Jobsite Table Saw
- Recommended:
- See others: https://amzn.to/417ipOk
- Dado Insert:
DCS7485B | 8 ¼” Flexvolt 60V MAX Cordless Table Saw
- Recommended:
- See others:
- Dado Insert:
DWE7491RS | 10” Jobsite Table Saw with Rolling Stand
- Recommended:
- See others:
- Dado Insert:
Zero Clearance Insert for SawStop Table Saw
SawStop offers OEM zero clearance inserts, which are the preferred and recommended option. They do come at a premium, but with those, you don’t have to worry about cutting an additional opening for the riving knife. You can purchase these inserts from any SawStop Dealer.
- SawStop Compact Table Saw
- Recommended:
- See others:
- Dado Insert:
- SawStop Jobsite Saw Pro
- Recommended:
- See others:
- Dado Insert:
- SawStop Contractor Saw
- Recommended:
- See others:
- Dado Insert:
- SawStop Professional Cabinet Saw
- Recommended:
- See others:
- Dado Insert:
- SawStop Industrial Cabinet Saw
- Recommended:
- See others:
- Dado Insert:
Zero Clearance Insert for Craftsman Table Saw
- CMXETAX69434502 | 10-in Carbide-tipped Blade 15-Amp Portable Jobsite Table Saw with Folding Stand
- Recommended:
- See others:
- Dado Insert:
- CMXETAX69434510 | 8.25-in Carbide-tipped Blade 13-Amp Portable Benchtop Table Saw
- Recommended:
- See others:
- Dado Insert:
- CMXETAX69434506 | 10-in Carbide-tipped Blade 15-Amp Portable Benchtop Table Saw with Folding Stand
- Recommended:
- See others:
- Dado Insert:
Zero Clearance Insert for Rigid Table Saw
- R4514 | 15 Amp 10in. Portable Corded Pro Jobsite Table Saw with Stand
- Recommended:
- See others:
- Dado Insert:
- R4518 | 15 Amp 10in. Portable Corded Jobsite Table Saw with Stand.
- Recommended:
- See others:
- Dado Insert:
- R4540 | Table Saw with Scissor Stand
- Recommended:
- See others:
- Dado Insert:
- R4550 | 10in. Table Saw with Folding Stand
- Recommended:
- See others:
- Dado Insert:
Types of Zero Clearance Inserts
Phenolic Zero Clearance Inserts
Phenolic plastic is a composite material resin used in several industrial applications. As a sheet, like when used for a zero clearance insert, it’s impact and abrasion resistant and very durable. It’s a plastic that’s cheap to produce and easy to work with.
Compared to MDF in a table saw application, it’s much more durable material and looks better too.
MDF Zero Clearance Inserts
Medium Density Fiberboard, or MDF, is commonly used as a cheap structural component to furniture, cabinetry, and speaker boxes. In terms of cost per square foot, this will be the cheapest option. However, don’t expect an MDF insert to last forever.
HDPE Zero Clearance Inserts
High Density Polyethylene, also known as HDPE is a thermoplastic that’s used in a wide variety of materials. It’s waterproof, durable, abrasion resistant, and relatively inexpensive. HDPE is commonly used in cutting boards. In fact, if the cutting board is the right thickness or you choose to install some adjustable feet, you can trim a store bought cutting board to size to use as a zero clearance insert.
Otherwise, there are HDPE sheets available online and even if you don’t use the entire sheet, this material can be used for all other sorts of table saw applications. For example, HDPE is commonly used to make runners for the miter slots when building any sort of jig or sled.
What are the benefits of using a zero clearance insert?
- Reduced risk of blow out
- Improved cut quality
- More control over the piece as it moves through the saw
- Prevents small pieces from falling through the throat
The most common reason woodworkers choose to use a zero clearance insert is because it greatly reduces the risk and occurrence of blowout. Blowout commonly occurs on plywood products and happens because of the wood grain running perpendicular to the saw blade.
When the blade makes its way through the material, it pushes those wood down and out of the material. Since the grain of the material is perpendicular and doesn’t have any support below it, it sometimes will pull wood that is adjacent to the width of the saw blade.
The result is wood that has a jagged edge that isn’t uniform. The video below shows what ‘blow out’ is with a circular saw. The concept is the same as the table saw.
With a zero clearance table saw, the material that is adjacent to the width of the saw blade has support and thus a clean cut can be made. This prevents blowout and improves the quality of the cut.
How to make a zero clearance insert
There are two main ways to create a zero clearance insert.
Method 1 is using your existing throat plate as a template to trace onto another piece of wood, HDPE, phenolic or other material. This is the fastest method, but can be inaccurate as there’s a greater margin of error when you’re tracing it.
Method 2 is removing the stock throat plate and then taking a measurement of the widths and radius. The throat on most table saws is essentially an elongated circle. Imagine cutting a circle in half and then putting a rectangle in the middle of the two circle halves that has the same width as the circle’s diameter - that’s your table saw’s throat shape.
With Method 2, once you figure out the length and width of the rectangle, then you can find the radius of the ends by dividing the rectangle’s width by two. To draw the radius, use a compass or find another round object that’s roughly the same size. Try using a soda can, a vegetable can, bottles, or other round objects.
Other Considerations and Alternatives
Make room for the riving knife / splitter
With nearly any zero clearance insert you buy and any plans you follow to create one, making space for the riving knife isn’t often mentioned.
Don’t forget about the riving knife.
After raising the blade through the insert to cut the initial opening for the riving knife, you’ll want to go back with a jig saw or hand saw and cut an additional opening in the rear for the riving knife. This keeps the material from getting pulled into the blade and taking your hand with it.
Need to prevent blow out immediately?
If you don’t have time to purchase or create a zero clearance insert, but need to prevent blow out a common method used is to put a good quality painter’s tape over the cut. Center the painter’s tape over where you’ll be cutting the material and continue with the cut.
Painter’s tape helps to provide support to the wood fibers and prevent them from blowing out. This method isn’t perfect and won’t always give perfect results, but it works in a pinch.