Hollow Grind?

[Corey Roberts]

Often I will read in catalogues, books and other such material that a sword blade is hollow ground. What exactly does this mean, and how does a hollow ground blade differ from other blades which are not. Also, what are the advantages of having a hollow ground blade, and or disadvantages?

[Byron Doyle]

It means that the edge has a concave cross-section. Generally this cross section allows a much sharper edge, but because the blade is going to be so thin approaching the edge, the edge will generally be less durable. You see hollow ground edges a lot on higher-end knives, but I don't know about swords. I haven't looked into it.

[Will Adamson]

Do you mean concave like an ice skate? This seems much more conducive to rather shallow slicing rather than cutting through. Is this the case?

[Byron Doyle]

No, it's exactly opposite. On an ice skate, the blade is hollow ground so there are two edges. On a hollow ground cutting blade, there will be two concave surfaces 'leading up to' one (very sharp) edge. Give me five minutes and I'll draw a diagram and post it here.

Edit: here's the diagram. I don't have specific measurements, but this is the general shape.

[Ben Strickling]

There's also an article here on MyArmoury.com that gives diagrams of some of the different blade cross sections.

[Will Adamson]

That makes more sense. We use the term hollow when refering to how deep skates are ground (like mine are 1/2") thus my confusion. It seemed odd to me that this would be done with swords or knives.

With an edge that sharp and delicate, what sorts of things would be done with knives of this type of grind? I would venture to guess surgical instruments possibly. I've never gotten to venture into medieval barber archaeology. Any thoughts?

[Byron Doyle]

I dunno about surgical instruments, but like I said a lot of higher-end knives have hollow ground blades. As far as I know most military-grade knives are hollow ground. This does indeed make the edge more delicate, but for knives they can use a much harder steel than you could a sword, as the knife really doesn't need to flex. This harder steel makes the edge easier to retain. Of course careful care comes into play here too, but I would imagine that through resharpening the hollow grind is worn away eventually.

Historically I would think that daggers more than swords would use hollow grinds for much the same reason as today's knives.

[Shane Smith]

On a sword, a hollow grind to a riser also makes the blade stiffer for the thrust while maintaining a wonderfully light weight.