Zero clearance insert

[Jerry Thompson]

If a zero clearance insert is used is a splitter necessary when ripping lumber?

[Brian Tymchak]

If a zero clearance insert is used is a splitter necessary when ripping lumber?

Yes. They are unrelated. A ZCI gives you a cleaner cut at the blade exit by supporting the wood on both sides at the cut edges. A splitter (or riving knife) keeps the board from pinching the back of the blade and causing a kick back.

[Michael Burnside]

Most certainly. As Brian points out they are unrelated.

[andy bessette]

I have been a professional woodworker for nearly 50 years and have never fount the need for a splitter. But I use only carbide blades, and virtually all wood is kiln dried.

[Maurice Mcmurry]

I too have never had a splitter. There are tasks where a Z.C.I. is a necessity. Don't forget to remove the Z.C.I. before tilting the blade. The same shop-mate that theatricality pronounced the saw broken after trying to tilt the blade with the zero clearance throat plate in later went on to get an injury from not putting it back.

[andy bessette]

One comment I'd like to make here regarding zero clearance inserts. Avoid plastic ones.

I had purchased on of these and had left it in place while cutting some plastic material (perhaps King Starboard). Unbeknownst to me the plastic swarf had built up at the back of the insert's kerf (under the workpiece), during the single cut, resulting in a huge explosion when the insert flew apart. Hurt the hell out of my thumb, but no blood.

[Brian Deakin]

I measured the thickness of the insert that came with my machine


I then went to a store that sold laminate flooring and identified a piece of flooring of the same thickness

(measured thickness with digital caliper or you could compare your insert with the flooring in the store)



I purchased a scarp piece of flooring and used it to make a zero clearance insert

[Maurice Mcmurry]

Mine are homemade from plywood, Corian and Swanstone. Thats a good reminder about cutting plastic and the dangers the swarth can cause. A good word too: Swarth

[Jim Morgan]

"Swarth" is a fine word, though I believe that the word you were looking for in this instance is "swarf."

[Maurice Mcmurry]

Thanks for the correction!