A table saw is a versatile machine that makes woodworking jobs much faster and easier. However, a table saw can also take a finger off (or two) if you’re not careful. So, you may wonder whether you can add a riving knife to a table saw.
You can add a riving knife to a table saw. Since 2009, OSHA has required every new table saw to have a riving knife. For older table saws, you can make a riving knife or buy one made for your brand of table saw. There is no universal riving knife, however.
Since a riving knife is a valuable safety mechanism, adding this feature to your table saw makes sense. Keep reading to see how a riving knife works, and how to add a riving knife to your table saw. Also, don’t confuse a riving knife with a splitter as they are two different table saw features.
How a Riving Knife Works
A riving knife has two main functions. The first is to stop the board you’re ripping or cutting from closing around the back of the saw blade where it can kick back. The second is to prevent the board from moving away from the fence which keeps the board stable.
When the wood board comes in contact with the rising saw teeth, this action can throw the board back into the operator. As you can imagine, this action can cause serious injury.
The Benefits of Adding a Riving Knife to a Table Saw
Adding a riving blade to your table saw will help you avoid dangerous wood kickbacks — some of which can fly back into your chest and cause internal organ damage. (I’ll explain kickbacks in more detail later.)
The reason is that the riving knife has vital features that protect you when using a table saw. These features/benefits are:
- The riving blade sits close to the back of the saw blade. This position reduces the chances of the wood shifting into the wrong blade path.
- The riving blade protects the table saw operator by blocking the back blade edge. The back blade edge is the most likely place for the wood to shift and kick back.
- The riving blade adds another layer of protection from accidents. Specifically, it augments the blade guards and other safety features.
- The riving blade is never removed from the table saw. That means it’s a permanent addition.
- The riving blade moves with the saw blade. As the saw blade raises, lowers, and tilts, so does the riving blade.
Differences Between a Splitter and a Riving Knife
While a splitter and riving knife are similar, you need to understand the differences between the two since they serve different functions. For one, the riving blade has a constant distance from the saw blade no matter its height as it moves with the blade height.
Meanwhile, here are the functions of a splitter that comes attached to a table saw.
- A splitter is stationary, set back from the blade to prevent the board from catching on the back side of the saw blade.
- When the saw blade is at full height, the distance between the splitter and blade is small.
- When the saw blade is lowered, the splitter stays stationary. Once the distance from the back of the blade is wide, the wood can catch and flip around.
Adding a Riving Knife to a Table Saw
No matter how often you do woodworking, adding a riving knife to your table saw can exponentially increase the safety of sawing. As you work with your table saw, you might have experienced or seen kickback.
Kickback occurs when the piece you’re working with makes an unexpected, sudden move in the wrong direction. Keep in mind that cutting with a table saw involves a moving saw blade that turns up to 100 miles (161 km) per hour.
At this speed, the force of the moving piece of wood can throw the wood into your head or chest, or the blade can pull your hand in and mangle it. So, the riving knife is a safety device that prevents the wood from flying out of the blade.
You can see a diagram that shows what happens when the wood kicks back out of the table saw here.
Riving Knife Installation
Fortunately, you can add a riving knife to almost any table saw. Remember that operating a table saw without this safety feature can result in a catastrophic accident.
Here is a list of materials that you’ll need:
- A riving knife template from an existing riving knife or the internet
- A piece of sheet metal slightly thinner than the saw blade
- A metal file
- Lubricating oil
- Calipers
- Permanent marker
- Clamps
- A steel punch
- A hammer
- A jigsaw with a metal cutting blade
- Red spray paint (optional)
Once you have the materials, follow these steps to create a riving knife:
- Clean the sheet metal with acetone.
- Trace the shape of the riving knife on the sheet metal.
- Make sure the height of the riving knife is one-half inch (12 mm) shorter than the saw blade.
- Cover the metal cutting blade with oil lubricant to cut out the knife shape.
- File the edges of the riving knife to smooth them.
- Optional: Spray the riving knife with red spray paint.
- Drill holes in the correct locations to mount on the saw.
This YouTube video shows you how to make a riving knife that attaches to your table saw for protection from kickbacks:
You can also buy a riving knife for a specific brand of table saw. However, bear in mind that there are no universal riving knives that fit all table saws.
Conclusion
Adding a riving knife to your table saw is a smart choice. The circulating saw blade moves so quickly that a board can catch and shift position in an instant. If the board shifts backward, it’ll hit the operator, possibly causing permanent or life-threatening injuries. Whether you buy a riving knife or make your own, this addition to the table saw reduces the possibility of losing a finger or worse.
