A table saw riving knife is a critical safety device that prevents kickback by keeping the kerf open behind the blade. Unlike a splitter, it moves with the blade during depth adjustments and bevel cuts, offering consistent protection. Using a riving knife reduces the risk of serious injury and is required on modern saws for safe ripping operations.
If you’ve ever used a table saw, you know the feeling of a workpiece suddenly launching backward at terrifying speed. That’s kickback, and it’s the number one cause of table saw injuries. But there’s a simple piece of metal that can dramatically reduce that risk: the riving knife.
In this guide, I’ll explain exactly what a table saw riving knife is, how it works, and why you should never run your saw without one. Whether you’re a beginner or a seasoned woodworker, understanding the riving knife is a game-changer for safety. Let’s dive in.
Key Takeaways
- What it is: A riving knife is a metal tab mounted behind the saw blade that stays aligned with the blade during height and angle changes.
- Prevents kickback: It keeps the kerf open so the workpiece cannot pinch the back of the blade, which is the main cause of kickback.
- Not the same as a splitter: A splitter is fixed and must be removed for bevel cuts; a riving knife moves with the blade and stays in place for most cuts.
- Essential for safety: Modern table saws (2011+ in the US) are required to include a riving knife, but many older saws lack one.
- Removal for some cuts: You must remove it for dado blades, grooving, or non-through cuts – always follow manufacturer instructions.
- Retrofit options: If your saw does not have a riving knife, aftermarket kits are available for many models, or consider upgrading to a saw that includes one.
📑 Table of Contents
What Is a Table Saw Riving Knife?
A riving knife is a thin, curved piece of metal mounted directly behind the saw blade. It sits in the same plane as the blade and follows the blade’s movement when you raise, lower, or tilt it. Its job is simple: keep the kerf (the gap left by the blade) open so the workpiece cannot pinch the back of the blade.
How It Works
When you make a cut, the riving knife enters the kerf right behind the blade. As the wood passes through, the knife holds the two sides apart. This prevents the wood from clamping down on the back side of the blade – which is exactly what causes the wood to be thrown back toward you (kickback).
Riving Knife vs. Splitter
Many older table saws use a splitter instead of a riving knife. A splitter is a fixed, straight metal tab that does not move with the blade. To make a bevel cut, you have to remove the splitter entirely. A riving knife, on the other hand, tilts and rises with the blade. That means you can keep it installed for bevel cuts, dado cuts (if the knife is removable), and most standard operations. The riving knife is a clear upgrade in both convenience and safety.
Why Is a Riving Knife So Important?
Kickback happens fast – in milliseconds. It can send a board flying with enough force to break bones or cause severe lacerations. The riving knife is your first line of defense against this.
Preventing Pinch Points
As you feed wood into the blade, the kerf naturally narrows behind the blade because of internal wood stresses or simple friction. If the kerf closes, the blade will grab the wood and throw it backward. The riving knife physically prevents that closure.
Mandatory on Modern Saws
In the United States, the ANSI/UL 987 standard has required table saws to include a riving knife since 2011. So any saw built after that date should have one. If you own an older saw or a contractor saw, it likely uses a splitter or no anti-kickback device at all. Upgrading to a riving knife is one of the best safety investments you can make.
How to Use a Riving Knife Correctly
Using a riving knife is straightforward, but there are a few key things to remember.
Always Keep It Installed (When Possible)
The riving knife should be in place for all through cuts – that means any cut that goes completely through the workpiece. That includes rip cuts, crosscuts, and bevel cuts. For non-through cuts (like dadoes, grooves, or rabbets), you will need to remove it because the blade doesn’t go all the way through the material.
Check Alignment
Your riving knife must be aligned perfectly with the blade. Most saws allow you to adjust the knife sideways. A misaligned knife can cause binding or poor cut quality. Use a straightedge against the blade and the knife to verify alignment.
Match the Thickness
The riving knife should be slightly thinner than the blade’s kerf but thicker than the blade’s plate. That way it fits into the kerf without binding. If you switch between thin-kerf and full-kerf blades, you may need to change the knife or use an adapter.
When Should You Remove the Riving Knife?
There are times when the riving knife must come off. Knowing these situations is critical for safety.
Non-Through Cuts
If you are cutting a groove or dado that does not exit the bottom of the work piece (e.g., a half-blind dovetail or a stopped dado), the riving knife cannot enter the kerf. Remove it for these cuts, but be extra careful about kickback – keep your hands clear and use push sticks.
Dado Stacks
Dado blades cut a wide flat-bottomed groove, and they often run below the table surface. A riving knife is not designed to work with dado stacks. Remove it, and again, use extra caution.
Thin or Narrow Workpieces
Sometimes when ripping a very thin strip of wood, the kerf may be too small for the knife to fit. In those cases, consider using a featherboard or a zero-clearance insert to reduce risk.
Always Reinstall After
It’s easy to forget to put the knife back on after a non-through cut. Make it a habit: when you finish a dado job, reinstall the riving knife immediately. Keep it in a designated spot near the saw so you never lose it.
How to Install or Replace a Riving Knife
If your saw doesn’t have a riving knife, or you need to replace a damaged one, the process varies by brand, but here are the general steps.
Find the Right Knife for Your Saw
Riving knives are specific to the saw model. Check your owner’s manual or search online for your saw brand and model plus “riving knife.” Aftermarket options exist for many older saws, but compatibility is key.
Installation Steps
- Unplug the saw. Safety first.
- Remove the blade guard and any other accessories.
- Locate the mounting bracket behind the arbor assembly.
- Slide the riving knife into the bracket and align the holes.
- Insert the locking pin or bolt and tighten securely.
- Adjust the knife so it is aligned precisely with the blade. Use a straightedge.
- Reinstall the blade guard and check clearance.
Retrofit Kits
For older saws without a riving knife, some manufacturers sell retrofit kits. For example, Delta and Jet offer kits for certain models. You can also build a shop-made splitter that attaches to the throat plate, but a true riving knife is much safer. If retrofit isn’t possible, consider upgrading your saw.
Common Myths About Riving Knives
Let’s clear up a few misconceptions that might keep you from using this safety device.
“It slows down my cuts”
Not true. A properly aligned riving knife does not affect feed rate or cut quality. In fact, it helps prevent binding that could slow you down.
“I don’t need it because I’m experienced”
Kickback doesn’t discriminate. Even pros get caught off guard. A riving knife adds a layer of protection that requires no skill to use – it’s always there.
“It interferes with my jigs”
Some jigs, like tenoning jigs, may require removing the knife. But many jigs are designed to work with the knife in place. Check your jig instructions. You can also make a simple slot in the jig to accommodate the knife.
“A riving knife and a blade guard are the same thing”
No. A blade guard covers the top of the blade. A riving knife prevents kickback from behind. They work together. Modern saws often combine them into one assembly.
Final Tips for Staying Safe
Your table saw is the most dangerous tool in the shop. A riving knife is a huge step toward safety, but it’s not the only one. Always use push sticks for narrow rips, keep the blade guard on when possible, and never reach over the blade. Stand to the side of the cut line, not directly behind the board.
And remember: a riving knife is only effective if it’s installed. Get into the habit of checking it before every cut. If you’re shopping for a new saw, make sure it comes with a riving knife – don’t accept “maybe” from the salesperson. It’s a non-negotiable feature.
Understanding the riving knife isn’t just about compliance; it’s about respecting the tool and protecting your hands. Now that you know how it works, go out and use your saw with more confidence and less fear.
Frequently Asked Questions
Can I use a table saw without a riving knife?
Technically yes, but it’s dangerous. Without a riving knife, the risk of kickback increases dramatically. Always use one unless you are making non-through cuts where it physically cannot work.
Does a riving knife prevent all kickback?
No device can prevent all kickback, but a riving knife stops the most common cause: wood pinching the back of the blade. Combined with proper feeding technique, it eliminates the vast majority of kickback incidents.
Can I install a riving knife on an old table saw?
It depends on the model. Some manufacturers sell retrofit kits. You can also add a shop-made splitter that attaches to the throat plate, but it won’t move with the blade. For maximum safety, upgrading to a saw with a factory riving knife is recommended.
What’s the difference between a riving knife and a splitter?
A splitter is fixed and does not move when you tilt or raise the blade. A riving knife moves with the blade, so it remains effective for bevel cuts and height adjustments. Riving knives are safer and more convenient.
Do I need to remove the riving knife for dado cuts?
Yes. Dado blades cut wide grooves and the riving knife cannot fit into the kerf. Always remove it for dado operations and reinstall afterward to stay protected for standard cuts.
How do I know if my riving knife is aligned?
Use a straightedge placed against the side of the saw blade. Check that the riving knife is exactly parallel to the blade plane. If it’s off, loosen the mounting bolts, adjust, and retighten. Misalignment can cause binding and poor cut quality.
