^He basically made his own cutter. Cutting a notch into the back of the blade make a little single saw tooth. I was wondering how he got that result (and that sound) with a blade. Had to rewind it to see what he was doing.
I used to have one of those carbide tipped knives for scoring and snapping carpet backer board. Bought it on the rec of some forum members for FR-4 and the like. I eventually lost it, and I just made my own out of an old jig saw blade stuck into a wood handle (like a tiny scythe, stuck in from the side at an angle). It dulls, but I am pretty good at sharpening things. It's essentially the same as a tip of a knife blade, except you use it backwards with the flat "spine of the knife" going into the cut and the sharp edge trailing behind. You just have to get the right angle. A bit of positive rake so it doesn't dig in and jam. Gonna post a pic, because it started out super crude and I eventually figured out what to remove from the handle to make it more efficient in size and shape and ergos.
Soda bottle cap for size reference
[Imgur](
)
The single bevel makes it "right handed," to score right against a straight edge.
In addition to scoring, I find it makes a great marking knife for metals and wood. For wood, you just gotta go light on the first pass or two. After you get through the surface fibers, you can make your mark/score as deep as you want, unlike with a regular marking knife.
I found this so handy, I eventually made an ambidextrous version, years later.
[Imgur](
https://i.imgur.com/aIuyZrd.jpg?1)
Heh, the original is a little burnt and has some melted parts on the blade, because I used it as a hold down while welding.