# Are sharp knives really safer than dull ones? **URL:** \ **Category:** Factual Questions\ **Created:** [August 30, 2000, 4:06am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295 "2000-08-30T04:06:28Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [August 30, 2000, 4:06am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/1 "2000-08-30T04:06:28Z")
I’ve been told often enough that sharp knives are safer than dull ones. And I even believed it. Sure, it makes sense. The duller the knife, the harder you have to press; and the harder you press, the more likely the knife is to slip. Consequently, I keep my kitchen knives scrupulously sharp. But I’ve never seen _proof_ that it’s true. Tonight I cut my thumb (no major damage). The raw potato I was slicing was softer than I expected. As a result, the knife went through the spud and into my thumb when I applied only a little pressure. So it appears there are cases when sharper is not better. The real question is which is safer overall, sharp or dull. Or is there an optimal level of sharpness? Has there ever been a scientific study to investigate it? Before anyone else beats me to it, I admit it wasn’t very sharp of me to have my thumb in the path of the knife. :wally ---
**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\ **Post date:** [August 30, 2000, 5:06am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/2 "2000-08-30T05:06:49Z")
I’d say it depends on the user. If the knife wielder is skilled with knives, then he’d want a sharp one, just as any experienced tool user wants a well-made tool in good condition. A dull knife or other tool in bad condition causes you to have to use it incorrectly and unnaturally, increasing the chances of a mistake. If the knife wielder is inexperienced, all bets are off, but a dull knife is probably safer. Of course, using a dull knife doesn’t let the user gain any experience with the correct tool, so you wouldn’t want to start out a beginning knife wielder with it. Arjuna34 ---
**Author:** ![Trout\_Mask\_Replica](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@Trout\_Mask\_Replica](https://boards.straightdope.com/u/Trout_Mask_Replica)\ **Post date:** [August 30, 2000, 5:11am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/3 "2000-08-30T05:11:37Z")
In my experience, injuries from sharp knives are less painful, heal more quickly, and are less likely to leave scars. ---
**Author:** ![darkcool](https://avatars.discourse-cdn.com/v4/letter/d/5f8ce5/32.png) [@darkcool](https://boards.straightdope.com/u/darkcool)\ **Post date:** [August 30, 2000, 7:26am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/4 "2000-08-30T07:26:20Z")
I used to sell knives. It depends on your definition of ‘sharp’ and ‘dull’. Given the same knife, say a sharp ‘Commercial Sabtier’ or a ‘J. A. Heinkles’, or a dull (used) one, the dull one is much safer because even a “dull” Sabatier is a dangerous cutting tool. A sharp one scarily so. ---
**Author:** ![JavaMaven1](https://avatars.discourse-cdn.com/v4/letter/j/cab0a1/32.png) [@JavaMaven1](https://boards.straightdope.com/u/JavaMaven1)\ **Post date:** [August 30, 2000, 8:08am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/5 "2000-08-30T08:08:48Z")
Coming from someone who handles knives on a very regular basis (culinary school student) a sharp knife cut is by far, the better of the two. When you have a sharp knife edge, the cut is going to be a very clean cut, and **Trout** was right about them also healing quicker and being less painful. The sharp blade will go straight through flesh like butter–but there is actually less damage, as a dull knife edge will sort of roll around in the flesh. The worst cut I recieved was with my bread knife, with its very serrated edge. That one took the longest to heal. (Of course, I got the cut when I was putting it in its protective sleeve, so I _wouldn’t_ get cut when reaching into my kit.) ---
**Author:** ![darkcool](https://avatars.discourse-cdn.com/v4/letter/d/5f8ce5/32.png) [@darkcool](https://boards.straightdope.com/u/darkcool)\ **Post date:** [August 30, 2000, 8:26am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/6 "2000-08-30T08:26:05Z")
That’s assuming you are using enough pressure to cut yourself with a dull knife as with the incident suggested by the OP. ---
**Author:** ![Danielinthewolvesden](https://avatars.discourse-cdn.com/v4/letter/d/ce7236/32.png) [@Danielinthewolvesden](https://boards.straightdope.com/u/Danielinthewolvesden)\ **Post date:** [August 30, 2000, 8:38am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/7 "2000-08-30T08:38:51Z")
I agree completely with Java. ---
**Author:** ![darkcool](https://avatars.discourse-cdn.com/v4/letter/d/5f8ce5/32.png) [@darkcool](https://boards.straightdope.com/u/darkcool)\ **Post date:** [August 30, 2000, 8:59am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/8 "2000-08-30T08:59:32Z")
Didn’t realise it was a contest. To specically answer the OP, If by safer you mean which will cut you (unitentionally) easiest, It’s the sharper knife (which I understood the OP to mean). If you mean which wound heals faster, I’ll defer to Java who apparently has more experience in that area and I’m guessing Dan does, too. I don’t cut myself enough to offer an opinion. 😉 ---
**Author:** ![JavaMaven1](https://avatars.discourse-cdn.com/v4/letter/j/cab0a1/32.png) [@JavaMaven1](https://boards.straightdope.com/u/JavaMaven1)\ **Post date:** [August 30, 2000, 9:09am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/9 "2000-08-30T09:09:08Z")
> [@](#): > > \*Originally posted by darkcool \* > \*\*That’s assuming you are using enough pressure to cut yourself with a dull knife as with the incident suggested by the OP. \*\* See, that’s the trick. If you’re working with a dull knife, you _have_ to use more pressure to cut. When the knife is sharp, you use less pressure, hence, less pressure going into your flesh. When we’re talking about dull knives, we’re not talking about butter knives, but things like French knives that are used for chopping large amounts of food. You do want these items to be as sharp as possible because it does make the task far easier. ---
**Author:** ![JavaMaven1](https://avatars.discourse-cdn.com/v4/letter/j/cab0a1/32.png) [@JavaMaven1](https://boards.straightdope.com/u/JavaMaven1)\ **Post date:** [August 30, 2000, 9:11am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/10 "2000-08-30T09:11:22Z")
> [@](#): > > \*Originally posted by bibliophage \* > \*\*Tonight I cut my thumb (no major damage). The raw potato I was slicing was softer than I expected. As a result, the knife went through the spud and into my thumb when I applied only a little pressure. > > Before anyone else beats me to it, I admit it wasn’t very sharp of me to have my thumb in the path of the knife. :wally \*\* I’m just wondering, exactly, how were you holding this said spud? ---
**Author:** ![darkcool](https://avatars.discourse-cdn.com/v4/letter/d/5f8ce5/32.png) [@darkcool](https://boards.straightdope.com/u/darkcool)\ **Post date:** [August 30, 2000, 9:17am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/11 "2000-08-30T09:17:48Z")
I see your point, but if you are using a knife correctly you won’t be cutting towards a bodypart. But you knew that. At least not for the average Joe. Now in culinary school you guys might get fancy, but again I don’t think that was the OP’s intent… ---
**Author:** ![JavaMaven1](https://avatars.discourse-cdn.com/v4/letter/j/cab0a1/32.png) [@JavaMaven1](https://boards.straightdope.com/u/JavaMaven1)\ **Post date:** [August 30, 2000, 9:35am UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/12 "2000-08-30T09:35:04Z")
> [@](#): > > \*Originally posted by darkcool \* > \*\*I see your point, but if you are using a knife correctly you won’t be cutting towards a bodypart. But you knew that. > At least not for the average Joe. Now in culinary school you guys might get fancy, but again I don’t think that was the OP’s intent… \*\* I’m just wondering–when you cut a potato, don’t you hold it down on your cutting board while you’re cutting it–or do you put it on the counter and whack at it à la \*John-Belushi-Samurai-\*Style? 🙂 But, seriously, fingers do sometimes get in the way when you’re holding items that you’re chopping. In that case, I’d rather it be sharp. ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [August 30, 2000, 1:11pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/13 "2000-08-30T13:11:46Z")
Research has shown that obsidian makes the most efficient, hence safest, cutting edge. It can take a sharper edge tha anything else. It can get down to single atoms. The cuts made into flesh with obsidian blades will heal faster than anything, with no scar at all. Goes to show that pre-Columbian American Indian surgeons with their obsidian knives were on to something that the white man has only recently discovered. ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [August 30, 2000, 1:19pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/14 "2000-08-30T13:19:31Z")
I routinely chip shards from a block of glass or obsidian to cut things. The edge on these tools is amazing, though brittle. ---
**Author:** ![Trout\_Mask\_Replica](https://avatars.discourse-cdn.com/v4/letter/t/a88e57/32.png) [@Trout\_Mask\_Replica](https://boards.straightdope.com/u/Trout_Mask_Replica)\ **Post date:** [August 30, 2000, 1:35pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/15 "2000-08-30T13:35:55Z")
> [@](#): > > \*Originally posted by ishmintingas \* > **Research has shown that obsidian makes the most efficient, hence safest, cutting edge. It can take a sharper edge tha anything else. It can get down to single atoms. The cuts made into flesh with obsidian blades will heal faster than anything, with no scar at all.** I don’t know why I didn’t mention this in my last post to this thread, but I took a class in prehistoric technology when I was in college, and one of the things we learned how to do was make tools out of obsidian. I cut myself a couple of times on obsidian fragments and most of the time it hurt barely at all – once I didn’t even realize I’d cut myself till I looked down and saw the blood oozing down my hand. While a fresh obsidian blade is much sharper than even the best surgical scalpels, obsidian can’t hold an edge nearly as long as, say, steel. You’re only able to get a few uses out of a blade before you either have to re-flake the edge or throw it away. ---
**Author:** ![Guy\_Propski](https://avatars.discourse-cdn.com/v4/letter/g/5e9695/32.png) [@Guy\_Propski](https://boards.straightdope.com/u/Guy_Propski)\ **Post date:** [August 30, 2000, 2:48pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/16 "2000-08-30T14:48:15Z")
People seem to be hitting all around this topic, without actually getting to the answer. The reason that dull knives are dangerous is that you have to use more force when cutting with them. More force means that it’s just that much more likely you’ll slip and cut yourself with the knife. A sharp knife, USED CORRECTLY, will therefore be safer. Bibliphage, I have to assume that you were holding the spud incorrectly when cutting it. If your thumb was in such a position that cutting through the spud brought it into contact with the knife, you would have cut yourself no matter how dull or sharp the blade. All I know about kitchen knives I learned from the Frugal Gourmet. ---
**Author:** ![Scylla](https://avatars.discourse-cdn.com/v4/letter/s/a5b964/32.png) [@Scylla](https://boards.straightdope.com/u/Scylla)\ **Post date:** [August 30, 2000, 3:11pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/17 "2000-08-30T15:11:59Z")
A point not mentioned: A sharp knife will grab, when lightly placed on an object prior to cutting preventing slippage. ---
**Author:** ![JavaMaven1](https://avatars.discourse-cdn.com/v4/letter/j/cab0a1/32.png) [@JavaMaven1](https://boards.straightdope.com/u/JavaMaven1)\ **Post date:** [August 30, 2000, 5:48pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/18 "2000-08-30T17:48:59Z")
> [@](#): > > \*Originally posted by Guy Propski \* > \*\*People seem to be hitting all around this topic, without actually getting to the answer. The reason that dull knives are dangerous is that you have to use more force when cutting with them. More force means that it’s just that much more likely you’ll slip and cut yourself with the knife. A sharp knife, USED CORRECTLY, will therefore be safer. > \*\* From the OP: > [@](#): > > The duller the knife, the harder you have to press; and the harder you press, the more likely the knife is to slip. From one of my posts: > [@](#): > > If you’re working with a dull knife, you have to use more pressure to cut. When the knife is sharp, you use less pressure, hence, less pressure going into your flesh. ---
**Author:** ![zwaldd](https://avatars.discourse-cdn.com/v4/letter/z/a9adbd/32.png) [@zwaldd](https://boards.straightdope.com/u/zwaldd)\ **Post date:** [August 30, 2000, 6:15pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/19 "2000-08-30T18:15:30Z")
i’m just going to throw this out there: a sharp knife is obviously a better tool than a dull knife (surgery, slicing tomatoes). but safer? the sharper the edge, the more likely you’ll get cut by incidental contact. i guess it depends on how dull the blade is and how insistent you are on using it in that condition. for me, a dull knife isn’t all that dangerous because i won’t use it to cut anything that requires the extra pressure. once i sharpen it though, i’ll have a useful, albeit more dangerous, tool. if a butter knife fell off the counter onto my bare foot, it would probably bounce off. if my favorite utility knife did that, there would definitely be a lot of blood. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 30, 2000, 6:21pm UTC](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295/20 "2000-08-30T18:21:18Z")
True for knives, and doubly true for axes. A dull axe will bounce out of the wood when you hit it, and land who-knows-where (but likely a leg or foot). One of the guys from my scout troop still has a very ugly, jagged scar on his right foot from a dull axe. So sayeth the _Boy Scout Handbook_, which is never wrong on such matters. [Next page](https://boards.straightdope.com/t/are-sharp-knives-really-safer-than-dull-ones/31295.md?page=2)