Why hollow grind?

[LJK]

My Calyipso Jr, Para Milli, and Dragon fly are such utterly superb cutter/slicers. I am wondering why hollow grind anything? Its also seems full flat would be easy and less expensive to mass produce. Hollow grind looks kinda cool. Is that it? Looks? :confused:

[Michael Cook]

:spyder: Compare by doing kitchen prep with each type. :) :spyder:

[Joe Talmadge]

I don't now about the current state of the art, but years ago hollow grinding was less expensive, not more. Easy to do: just run the blade past a couple of rotating wheels. Flat grind required a bit more work, a belt running past a platen or whatever. Maybe Sal could enlighten us as to which is less expensive to do these days.

Otherwise, done right, you end up with less metal behind the edge with a hollow grind: higher performance for shallow cutting, easier sharpenability, but weaker edge. I'm a fan of full flat over a shallow sabre hollow grind, but high hollow grinds are pretty impressive.

Joe

[The General]

Its worth remembering that the Sebenza is hollow ground.

I agree with Joe that it was certainly true then and may still be that it was cheaper to produce hollow ground blades. However I would argue that to many a hollow ground blade looks more attractive that a full flat ground knife.

Full flat ground blades tend to look rather plain, though I must admit I prefer the performance and toughness of a full flat blade.

I wonder if the origional Cally failed in no small part to its full flat grind. It is a great knife but perhaps the NKP just does not appreciate the look.

[LJK]

Are not most good kitchen knives flat grind? Mine all seem to be.

[Joe Talmadge]

Full flat is the way to go for most kitchen knives

[zackerty]

I have been a maker since 1975, and seriously since 1992.

Hollow grinding is way easier, uses less belts and less "hand and arm" power.
Flat grinds are more efficient, but years down the line, the primary edge ( the edge you sharpen ) tends to have a thicker profile than a hollow grind would at the same age.
Hard use knives should be flat grind... :)

[LJK]

Thanks for all the great info. Seems like cost than looks are the main reasons to hollow grind. For me I would be happy with all flat grinds. How about convex grinds (ala BRKT) Has Spyderco ever put any convex grinds on their knives?

[dialex]

Convex grinds are still very difficult to make for mass production knives, so I guess it will take a while.

[Jimmy_Dean]

for kitchen use, there is just no contest.

It doesn't mean hollow grind is obsolete though.
First I love the way it looks and it usually combines a very thin edge(good slicer) with a fairly thick spine(very tough). Plus, as you 'sharpen you way up the blade', the edge remains super thin, while a full flat will get progressively thicker.

it's got a lot of good qualities that make it desirable. But in the kitchen, it's downright horrible. It kinda wedges itself in hard food and breaks food more than it cuts it. Try cutting potatoes with a hollow grind one day and you'll get my drift.

well, nice thread!

-Dean