Makita LS1013 - Kerf Block Quickie
 

Hi

I've just bought a Makita LS1013 Sliding mitre saw and this is supplied
with a semi circular bit of plastic which is a "Kerf Block" according
to the manual.

This is supposed to screw just behind the fence in the middle and
presents a flat surface in line with the metal fence.

As the manual is total cobblers on this thing, could someone who has a
LS1013 or similar tell what does this "Kerf Block" do, when would I use
it and why (worryingly) if I screw it where they say, and push the
blade all the way towards the fence, it will neatly slice this block
into two bits!!!!.

Thanks in advance

Graham