How to determine splitter or riving knife thickness
These are our typical recommendations on which thicknesses to choose when ordering. The thicknesses we offer are actually just standard steel gauges. 13, 12 and 11. The smaller the number, the thicker the stock.
Most older factory supplied guards use 14 gauge and even less in some cases.
Until recently, this was typical. Now with newer saw designs coming out that are
equipped with riving knives, more and more are shipping with .090 inch thick factory knives.
These are the thicknesses we start out with. There is a tolerance and generally my material is a bit under my posted thicknesses and rarely do they finish out above it.
When it is thicker, it is very minimally so.
It has been our experience that getting a splitter very close to the blade thickness is bad. It can often result in sticking, pinching or otherwise binding on nearly every cut. This is also not safe. It will cause you to want to apply more pressure to feed and that is undesirable.
You may have seen guys cut lumber the exact thickness of the kerf and use this as a splitter mounted into the throat plate. The reason that works is because the splitters are so small in area, they don't have enough surface to cause much friction. The larger area of bigger splitters will cause issues if they are too thick. We only sell a few of the thickest versions. They would be ideal on a saw in a cabinet shop that was dedicated for sheet goods. They also work on saws that have an easily adjusted splitter mounting bracket. Some are easy and some can be a bear.
We sell the thin kerf the most. .090 inch thickness. We recommend these for guys that use both type blades. Thin kerf and standard kerf. It actually works well for both because of the area of the splitter surface. Guys that don't own any thin kerf blades usually order the .105 inch. These are just a little thicker and may even support the guard just a bit better because of it.
You need to check your thin kerf blades with a caliper or micrometer before ordering.
In the past few years, some blade manufacturers are pushing the limits with ultra thin kerf blades.
We feel theses are too thin to use safely. The best option is not to buy blades that thin.
If the blade is too thin to use the factory safety equipment, then how wise of a purchase can it really be?
To sum up, a good splitter or riving knife should be just a bit less than the thickness of your kerf. Safety should be easy and trying to use a splitter that is too thick is a step in the wrong direction. .