If your table saw did not originally come equipped with a riving knife, retrofitting one is generally not feasible. This article explains why adding a riving knife to an older or non-compatible saw design poses significant technical and safety challenges.
What Is a Riving Knife?
A riving knife is a safety device mounted behind the saw blade. It moves in unison with the blade, maintaining a consistent gap and reducing the risk of kickback by preventing the workpiece from pinching the blade during cutting.
To function properly, the riving knife must:
- Stay at the same distance from the blade at all times.
- Raise, lower, and tilt with the blade.
- Remain close to the top of the blade without extending above it, allowing for through and non-through cuts.
Why Retrofitting Doesn’t Work
Older saws and non-riving-knife-equipped models typically have a blade that moves in an arc as it is raised or lowered. These designs use a stationary splitter, not a riving knife. The splitter does not move with the blade, and this creates several problems:
1. Inconsistent Blade-to-Knife Distance
As the blade travels in its arc, the distance between the blade and splitter changes. A proper riving knife must maintain a constant distance, which is impossible with an arc-style blade lift without extensive redesign.
2. Lack of Vertical Synchronization
A riving knife must stay aligned with the top of the blade throughout height adjustments. With a fixed splitter, this alignment is lost. When the blade is lowered, the splitter stays too high, potentially interfering with the workpiece and defeating the safety purpose.
3. Extensive Modifications Required
To retrofit a true riving knife, you would need to:
- Replace the internal blade carriage or trunnion system
- Modify or replace castings inside the saw
- Engineer a system that maintains synchronized blade/knife motion
These changes are not only cost-prohibitive but also structurally impractical for most table saw designs.
Final Note
Retrofitting a riving knife is not supported for machines that were not originally designed for one. If you’re concerned about kickback or safety features, we recommend considering a modern table saw that comes equipped with a factory-installed riving knife and updated safety systems.
For more information on choosing a safer table saw or understanding the differences between riving knives and splitters, feel free to contact our technical support team.