Is a dull knife more dangerous than a sharp one?

Joined
Feb 10, 2014
Messages
4,120
I always hear people saying stuff like "a dull knife is more dangerous than a sharp one." I don't really agree. While it might be more likely to make a mistake with a dull knife, one mistake with a sharp one has huge consequences. So what do you think is more dangerous?
 
Joined
Jan 9, 2007
Messages
31,071
Dull.

1) You are using more force to cut. That greater force is imparted into whatever part of you you happen to contact.
2) The cut is not as clean as the cut from a sharp knife. Not only is it nastier...it hurts more.
 
Joined
Jan 31, 2012
Messages
4,704
Dull.

1) You are using more force to cut. That greater force is imparted into whatever part of you you happen to contact.
2) The cut is not as clean as the cut from a sharp knife. Not only is it nastier...it hurts more.

This. Plus you are more likely to make a mistake with a full know than a sharp one.
 
Joined
Feb 10, 2014
Messages
4,120
Dull.

1) You are using more force to cut. That greater force is imparted into whatever part of you you happen to contact.
2) The cut is not as clean as the cut from a sharp knife. Not only is it nastier...it hurts more.

I agree you are using greater force, but only because that greater force is needed for the knife to cut. So though the greater force IS imparted on the part of you that you cut, it should be relative to the extra effort needed for it to cut you in the first place. By this logic they would be equally dangerous, no? I agree that cuts from dull knives hurt more, but in my experience they bleed less.
 
Joined
Jan 9, 2014
Messages
527
In my opinion, there is a lot of truth to that old saying, for a variety of reasons. If a knife is dull, it requires much more pressure to cut through a given item than if it were sharp. More pressure means less control and a higher likely hood of a slip as well as a very large impact in the case of a slip. A dull knife also doesn't bite in the way a sharp one does making a slip more likely. Cutting with a sharp knife is effortless and therefore much more controlled.

Now like you said, a sharp knife can obviously be dangerous too, especially in the hands of someone who is used to dull knives. Such a large part of the population is used to dull knives (especially in the kitchen) that they no longer respect knives the way they should. If you are expecting to get a cut at the slightest contact with your knife's edge you will be very careful while using it.

For someone who is paying attention, knows that their knife is sharp and is using it properly: a sharp knife is safer than a dull knife.
 
Joined
Jan 9, 2007
Messages
31,071
I agree you are using greater force, but only because that greater force is needed for the knife to cut. So though the greater force IS imparted on the part of you that you cut, it should be relative to the extra effort needed for it to cut you in the first place. By this logic they would be equally dangerous, no? I agree that cuts from dull knives hurt more, but in my experience they bleed less.

No. As scurvy noted, the force needed to use a dull knife is also what is usually going to cause you to make the mistake.

I suppose one could argue the theory of depth of cut by less force/sharper vs more force/duller if one wanted to. Seems academic.
 
Joined
Feb 10, 2014
Messages
4,120
In my opinion, there is a lot of truth to that old saying, for a variety of reasons. If a knife is dull, it requires much more pressure to cut through a given item than if it were sharp. More pressure means less control and a higher likely hood of a slip as well as a very large impact in the case of a slip. A dull knife also doesn't bite in the way a sharp one does making a slip more likely. Cutting with a sharp knife is effortless and therefore much more controlled.

Now like you said, a sharp knife can obviously be dangerous too, especially in the hands of someone who is used to dull knives. Such a large part of the population is used to dull knives (especially in the kitchen) that they no longer respect knives the way they should. If you are expecting to get a cut at the slightest contact with your knife's edge you will be very careful while using it.

For someone who is paying attention, knows that their knife is sharp and is using it properly: a sharp knife is safer than a dull knife.

Nice response. What made me post this thread was the other thread asking what non knife people think about sharp blades. A number of people said they feel them and cut themselves. My girlfriend needed a knife for some hair doing stuff and ended up cutting through her fingernail. Of course it was all my fault for keeping it too sharp.
 
Joined
Oct 9, 2013
Messages
1,509
It might also come into play that you'll have overconfidence to not get cut with a dull knife.
 
Joined
Aug 26, 2013
Messages
410
Dull. It's a classic saying over the generations for good reasons. For all the reasons above.

All knives are dangerous. Dull knives invite mistakes. Too much force. Annoyance/aggravation. Clumsiness. And in a split second, somebody has gone from just using a dull knife to needing wound care.

And while a dull knife is dangerous, a dull hatchet or dull axe is infinitely more dangerous than a sharp one.
 
Joined
Jan 9, 2007
Messages
31,071
Nice response. What made me post this thread was the other thread asking what non knife people think about sharp blades. A number of people said they feel them and cut themselves. My girlfriend needed a knife for some hair doing stuff and ended up cutting through her fingernail. Of course it was all my fault for keeping it too sharp.

The "fault" with a sharp knife is not paying attention. Everybody's guilty of that.

A story. Couple years ago I was chopping in the kitchen, being lazy and I hit my nail. I didn't even want to look...I figured it was gonna be bad and I just hadn't felt it yet. Eventually looked and I had sheared a layer of my nail off without hitting skin. Scagel knows what a dull knife would have done. I shudder to think. Still gives me the willies.
 

CapitalizedLiving

Gold Member
Joined
Dec 1, 2007
Messages
3,740
Dull knives are more dangerous in my experience. I'm used to my kitchen knives being razor sharp, and when they are any less I immediately notice a reduction in control and a lower sense of how much pressure is appropriate, both of which are safety hazards.
 
Joined
Mar 19, 2012
Messages
1,489
Not always.

Hand a non-knife person a "razor sharp" knife, there's more chance they will cut themselves. Same goes for children, are the dull table knives or steak knives they usually handle more dangerous than a screaming sharp blade?

In addition I've cut myself on "razor sharp" knives a lot more than with dull knives. One could argue you won't cut yourself if you handle the knife safely and properly but that would also be true for a dull knife.


There's truth to the statement but it's not true in every situation, it's an old saying but it's not gospel.
 
Joined
Jan 9, 2014
Messages
2,485
When playing with your knives, dull is safer. When using them to actually cut, sharper is safer. Every time.
 
Joined
Jan 9, 2014
Messages
527
Thanks.

I was reading that thread earlier, my experience has been similar.

I know how ya feel, I've been blamed for sharpening our knives at home and forgetting to notify the family!

Your example is probably a good one of the user not expecting the knife to be as sharp as it was, or perhaps not being as attentive as they should've been. No offense to your girl friend of course! We've all been there, all it takes is a moments lapse of concentration or a hasty move (regardless of how sharp or dull the blade is)


Nice response. What made me post this thread was the other thread asking what non knife people think about sharp blades. A number of people said they feel them and cut themselves. My girlfriend needed a knife for some hair doing stuff and ended up cutting through her fingernail. Of course it was all my fault for keeping it too sharp.
 
Joined
Feb 10, 2014
Messages
4,120
Thanks.

I was reading that thread earlier, my experience has been similar.

I know how ya feel, I've been blamed for sharpening our knives at home and forgetting to notify the family!

Your example is probably a good one of the user not expecting the knife to be as sharp as it was, or perhaps not being as attentive as they should've been. No offense to your girl friend of course! We've all been there, all it takes is a moments lapse of concentration or a hasty move (regardless of how sharp or dull the blade is)

No offense taken. And she knows my blades are sharp cuz she sees me sharpening them and inspecting the edge with a hand microscope, so its inattentiveness with no excuse! Off with her head! Or at least half her nail. Next day she used it as an excuse to get her nails done(the nail hadn't fallen off yet). A day or so later she had nine beautiful nails and one fugly half nail where the fake had fallen off with the top part of her nail. lol
 
Joined
Jan 3, 2013
Messages
5,713
It depends.

If you are going to cut something, then a dull knife is definitely more dangerous to use on the task.

If you are going to drop it on your foot, act careless..... etc.... then the sharper knife is more dangerous.
 
Joined
Nov 20, 2005
Messages
19,385
In my opinion, there is a lot of truth to that old saying, for a variety of reasons. If a knife is dull, it requires much more pressure to cut through a given item than if it were sharp. More pressure means less control and a higher likely hood of a slip as well as a very large impact in the case of a slip. A dull knife also doesn't bite in the way a sharp one does making a slip more likely. Cutting with a sharp knife is effortless and therefore much more controlled.

Now like you said, a sharp knife can obviously be dangerous too, especially in the hands of someone who is used to dull knives. Such a large part of the population is used to dull knives (especially in the kitchen) that they no longer respect knives the way they should. If you are expecting to get a cut at the slightest contact with your knife's edge you will be very careful while using it.

For someone who is paying attention, knows that their knife is sharp and is using it properly: a sharp knife is safer than a dull knife.

Cutting with a knife is all about control and it is harder to control a dull knife and do the same amount of cutting. So, I agree with this excellent post.
 

jc57

Gold Member
Joined
Nov 28, 2012
Messages
8,589
Really depends on how you plan to use the knife. There are plenty of things that need a narrow edge of metal that doesn't need to be extra sharp to cut it, and so a dull blade will do that job just as well, and is more forgiving of careless handling.

I can cut most prepared foods quite easily using the relatively dull edge of table flatware, and there is ZERO danger of injury in that usage case. The exception would be certain types of meat. Now if the job really called for a sharp knife, such as cutting up the RAW foods that haven't been cooked yet, then the table knife probably wouldn't even be up to the job. This is why you have sharp kitchen knives, and moderately sharp steak knives.

The times when a dull knife is dangerous, are those times when you actually do need a sharp knife, and have to compensate by using more force.

So, I don't put a razor edge on butter knives, but I do want a very sharp edge on something I will be using to cut carpet tiles.
 
Joined
May 25, 2013
Messages
3,700
Nice response. What made me post this thread was the other thread asking what non knife people think about sharp blades. A number of people said they feel them and cut themselves. My girlfriend needed a knife for some hair doing stuff and ended up cutting through her fingernail. Of course it was all my fault for keeping it too sharp.

Funny story, a couple of months ago I was cutting a tomato. I was using a kitchen knife that my girlfriend makes me intentionally keep extra dull so she doesn't cut herself. :rolleyes: So there I am with a half cut tomato, trying to make another slice. The thing was so dull I was sawing and putting extra force and the whole tomato just kind of "rolled" and the knife came down on my finger. Cut it pretty good. Not worth stitches, but worse than I've done with any of my "dangerously sharp" knives in the last 20 years. Well, guess what? That was all HER fault for making me keep the knife so dull!!! :eek: See?? Two can play at that game! ;)
 
Joined
Feb 10, 2014
Messages
4,120
Funny story, a couple of months ago I was cutting a tomato. I was using a kitchen knife that my girlfriend makes me intentionally keep extra dull so she doesn't cut herself. :rolleyes: So there I am with a half cut tomato, trying to make another slice. The thing was so dull I was sawing and putting extra force and the whole tomato just kind of "rolled" and the knife came down on my finger. Cut it pretty good. Not worth stitches, but worse than I've done with any of my "dangerously sharp" knives in the last 20 years. Well, guess what? That was all HER fault for making me keep the knife so dull!!! :eek: See?? Two can play at that game! ;)

LOL excellent! Funny how it wouldn't cut the tomato, but as soon as it hit your skin it turned into a slicer! Tomatoes in particular I would say I prefer a crazy sharp edge to cut. Reminds me of another story when I was out having sushi. The sushi chef was talking to me about how sharp his knives were after I showed him my pocket knife. He demonstrated by dropping a cucumber(held horizontally) from a foot over the blade-up knife. It went a little more than halfway through...I was merciful and left him with his pride. Funny thing was my girlfriend was SUPER impressed...she's still learned nothing. On the bright side, I got her to finally carry a knife after getting a pink mini tuff lite a few weeks ago...Yesterday she asks me, "Do I have that little pink knife, or do you?" Great, she has it and will have to ask for time to look through her purse to get it.

Back on subject, it seems the context makes a big difference of weather dull or sharp is more dangerous.

Robber: "Give me all your money, I have a sharp knife!"
Victim: "Well I have a dull knife, which we know is more dangerous!"
Robber: Stab

It seems the dull knife was still more dangerous to use.
 
Top