It took me a while to get the hang of all the different types of knives we make here at YSK. There are three I was particularly surprised by: not only did they not *look* like what I would, at that point, consider a knife. In some cases, they didn’t even seem to *do* what I thought knives were made to do.
I know better now, although I do occasionally find a need to point out this truth to others.
So, to satisfy your weekly trivia fix, please enjoy this little primer on 3 Machine Knives you may not have thought were knives (but they are knives, I promise!!):
Toothed Circular Knives
Oh look! A round blade with teeth!! Must be a saw, right? Wrong.
One major difference is that a saw blade’s kerf (the width of the cutting edge) is wide enough to yield material waste during the cutoff process. Think sawdust. Conversely, circular knives, even those with teeth, are precision sharpened to razor-thin. The width of a knife’s cutting edge is so fine that it separates one piece of material into two causing little to no material waste.
Toothed circular knives are the heroes of many industries. In food processing, they shear meat without a wince. In packaging, they help shorten paper tubes and other dense materials.
Here’s another slightly tricky one. Scoring knives (aka “paper scoring knives” or “creasing knives”) are still considered knives even though they don’t physically separate a material into two parts.
Scoring knives are particular prominent in the printing & packaging industries, where paper and cardboards are scored to make for easier folding.
Could you imagine ordering a bundle of moving boxes and having to crease the sides and flaps yourself? Or being a factory worker who had to do that by hand before packaging could be filled with product?I sure wouldn’t want to do either…
Perforating knives are another type of machine knife that do not particularly separate a material into two pieces (as we’ve come to assume all knives do). Instead, they help make it *easier* to separate material into piece further down the line by taking out alternating bits of material along a defined path.
Perforations are everywhere: coupons, stamps, even toilet paper. Thousands of products we use every day are used easier with the help of perforations.
Perforating knives can be straight or circular in configuration. They can be engineered to punch holes, slits, dots, and dashes. Whatever it takes to get the job done.
Bonus #4: The Infamous Paper Tube Saw. Ok, seriously, this guy is neither infamous, nor is he a saw. Paper tube (or paper core) saws are simply toothed circular knives with an industry-specific nickname. A nickname I was particularly hung up on in my early days here with the YSK team. But remember: no kerf. No saw.
So there you have it, three (plus one) incredibly common knives that don’t particularly seem like knives at all. Of course, this is a very basic primer, and there are a myriad considerations to make when designing a knife for any operation: material, purpose, coating, and environment to name a few.
But, that’s a post for another day!