Argument at work between which would dull faster: Serrated or straight edge knife cutting oranges?
Not sure that’s really a valid question. A straight knife will do a good job when sharp, and a poor job when dull. A serrated knife will do a poor job when sharp, and a poor job when dull.
So if the question is: how long until it starts doing a poor job, then the straight knife wins. If it’s how long until it starts doing a noticably poorer job than when new, then the serrated one wins.
Right on Viking! All my pocketknives are plain edged, for my last one I had to special order it as all they had at the shop were combo edge (front plain and back serrated)
A serrated edge relies on the change in angle of the blade to the surface being cut whereas a straight or plain edge knife actually needs to be sharp to cut.
I’m assuming you are referring to pocket knives as the only serrated kitchen knives are bread knives and there you want the serrations to help split the bread as you are cutting it.
Get a good quality tool or high carbon steel knife and get it sharpened professionally, then run it across a sharpening steel (it doesn’t really sharpen it, it just smoothes the edge up so it cuts better) before use and you will be in good shape.
Every single knife in my cheapo knife block is serrated. We can’t all buy Sabatier, man!
A knife collector here,
Mike G is spot on. I came up with some good examples and extra material to back it up and just had to share. Sorry. 
The biggest consideration between plain and serrated is what you are cutting and how you are cutting it. For the paper slice or shaving test of sharpness, plain edge wins hands down. It has to slide a bit to do that and a serrated one will catch and tear/rip like a dull saftey razor. For things like rope, cable ties, bread and other rough cuts a serrated edge will cut better. Instead of one long slice it makes a lot of short slices and the serrations ride across the material.
The razor idea is the best way to think of this. A clean, sharp razor will just slice right through the hair in one stroke. A slightly dull razor (think very tiny serrations) will slice part way, catch and grab it jumps a tooth, slice a bit more, and repeat.
If thats not enogh. Ask the experts at The Blade Forums .
Here I thought it was going to be the obvious grammar question of why is the plural of knife “knives”.
[Immature giggling]
As Shoshana said, this isn’t a true statement - a great many of the kitchen knives sold are serrated, particularly those with impressive-sounding claims such as ‘never requires sharpening’.
Now to a chef, this is possibly a horrific state of affairs, but the fact remains that there are a lot of serrate non-bread kitchen knives on the market.
I think the reason that they never need sharpening is that they ‘saw’ rather than slicing - when they are new, the saw teeth are incredibly sharp and so they appear to slice really well - as the edge begins to dull, they still cut, but relying more and more on the saw function of the teeth. This process is sufficiently gradual that they user never notices a point where the knife isn’t slicing properly.
Even if we just stick to quality traditional kitchen knives, you’ll also find a tomato knife in some kitchens (14cm/5.5inch). So that’s two serrated knives out of five in my case.
Well, I suppose you could call those kitchen knives. 
Let me paraphrase; the only serrated knives that have any business being in your kitchen are bread knives and maybe a tomato knife. (although a nice sharp Granton knife will always do a better job)
IMHO,YMMY, etc etc ad infinitum
With good serrations like Spyderco’s ( http://www.spyderco.com ) and the same hardness and initial sharpness of the steel a serrated blade should cut better longer if it’s a ‘pulling through’ cut since there is more length to the edge due to the serrations.
Yeah, I’ve owned a Spyderco Rescue, Police and umm, another one I forget the name of which,all of these were serrated. I was not a huge fan of their steel (AUS?) although the Rescue was a fine knife for cutting through seatbelts.
As to the increased length, I personally do not believe the 1/4" max (yes I’m guessing) increase will make a difference. In fact after thinking about it, I wonder if the bottoms of the serrations are even touching the surface being cut. It seems that the cut would be held open by the sides of the serration and that would keep the entire blade length from touching. This would negate any length improvement.
To clarify, if you think of the serration as a curve, the only part of the serration that is “working” is the back 60% crescent of it as the forward portion is facing the wrong way.
I much prefer ATS34 or M2 tool steel for knife blades.
The argument arose from what is best in cutting oranges. We have a orange juice machine at work that slices oranges in half by squeezing them against a serrated knife - there is no cutting motion involve with the knife, they are just firmly pressed against the knife.
I argued a straight edge would be better because we could sharpen it when it became dull, though others said that because it was serrated it wouldn’t dull. Of course, I argued in silence, that a knife (any knife) will dull, and therefore a straight edge one, which we could sharpen ourselves, will outlast a onetime only serrated knife.
Youre somewhat right. First off a plain blade wont cut unless it slides. Your juicer would have to at least vibrate the orange to get the straight blade to slice. It is possible to sharpen serrations, you have to use a small file or stone instead of a flat file or stone as with a straight edge. Its harder to do, but like you said a serrated blade has a longer service life between sharpenings, so you don’t have to resharpen it as often as a plain edge.
[QUOTE=NevarMore]
First off a plain blade wont cut unless it slides. QUOTE]
Should push cut fine if the edge is sharp enough. ‘Serrations’ might actually be on the blade to some how reduce ‘drag / suction’ when pushing the oranges through the blade.
Surely one of my past wives, or any one of several dwarves, or perhaps even an intelligent member of a pack of wolves, could answer your question about knives.
Loaves need knives, as calves have hooves and thieves use scarves.
8o)