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. .090”, .105”, and .120”. 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 our material is a bit under our posted thicknesses. Within .003”. This is due to manufacturing the brushed finish on the splitters and riving knives.
We use brushed finish 304 and 316 stainless steel for all splitters and riving knives.
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, that is until recently. We recommend these .090” for folks that use both type blades. Thin kerf and standard kerf. It actually works well for both because of the area of the splitter surface. Folks 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 blades with a caliper or micrometer before ordering. You can also make a stop cut in a piece of material and measure the resulting slot cut by the blade. This is probably more accurate than using a caliper on the blade teeth. In the past few years, some blade manufacturers are pushing the limits with ultra thin kerf blades. We feel that these are too thin to use safely. The best option is not to buy blades that thin. For more table saws 3HP or higher, thin kerf blades tend to be a bit wobbly. We used to sell mainly thin kerf splitters and knives, but as of late, full kerf (1/8”) are becoming the norm again, and with good reason. Choose your blades wisely. If the blade is too thin to use the factory safety equipment, then how wise of a purchase can it really be?
The kerf thicknesses of blades from what we have experienced are as follows….
Thin Kerf……091”-.098” Optimum splitter thickness we provide. .09”
Standard Kerf……. .110”-.118” Optimum splitter thickness we provide. .105”
Full Kerf….. always 1/8” or .125” Optimum splitter or riving knife thickness is .120”
Some teeth on blades taper down in thickness to the blade body. So if you have this type of blade sharpened, the kerf thickness of the teeth will be narrower. This is why we encourage you to measure the width of the teeth of your blade with a micrometer before placing an order.
We can make special order ultra thin splitters and riving knives, but for each different model we sell, there may be issues that will arise when using thinner stock. Just email if you need something thinner, for example 8” diameter blades, and we will let you know what differences you might see or if it is even possible on your saw. We can also custom make riving knives and splitters for use with 8” blades so they will sit closer to the blade helping to prevent a kickback.
Some customers use multiple different thickness blades that have a wide range of kerf thicknesses. I must recommend you purchase a splitter or riving knife that corresponds with the kerf thickness of your blade. We can make many different thickness splitters and knives. If you have a custom need feel free to call or email. If you purchase a delta ARK package and need different thickness knives, or have an old unnamed saw that we have to custom make a splitter or riving knife for, and you use a multitude of blades on that saw, we will give you a discount for purchasing multiple knives or splitters depending on the length and width size they are. For a Delta ARK knife, additional knives are $30 as an example.
Some customers are comfortable using full kerf blades with thin kerf riving knives and splitters. I do not recommend this. I have had numerous customers contact me and say that there is burning on the wood they cut. This is caused by the new blade they bought that happened to be a full kerf blade and they had a thin kerf splitter or knife installed. This is dangerous to not pay close attention to so please understand the kerf thickness of your blade.
Pay close attention to the alignment of the splitter or knife as well. If you experience binding of wood on the splitter or knife, but know you have ordered the correct thickness, make sure that it is in proper alignment with the blade. Sometimes the trunnion can be slightly out of alignment and will throw the knife off on the back end causing binding of the wood. This is not common, but it happens even with new saws. We’ve pretty much seen it all here. There are many youtube videos on how to align trunnions to the blade.
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.