Why serrated edge blades?

Y

yankytrash

New member
Just wondering, really. Why do people seem to be leaning toward half-serrated edges on their blades? Being in construction where I use a blade constantly, seems like it'd be more of a pain in the wazoo than anything else.

Why do you pick'm?
 
My every day knife is a fully-serrated spydie. It works great for me. It does everything and I've yet to run into anything where I wished I had a plain blade.

I wouldn't choose serrated for a purely defensive knife, but for a working knife, I've been happy.

- Gabe
 
Serrated edges are for cutting with a sawing motion (like cutting bread), plain edges are for push cutting (like cutting through a carrot or chopping onions).

I don't care for 1/2 serrated knives anymore, but they are a comprimise--you can use the serrated portion for cutting rope,etc and use the plain edge for more delicate work.

The serrated edge does have the benefit of holding its edge longer than a plain edge. If you use a knife to open lots of boxes at work, cut a lot of strapping, etc, a serrated edge will perfom longer in between sharpening sessions.
 
At the one day knife defense course I took at the S&W Academy, taught by a 10 year veteran, he recommended plain edged blades only. He said tests on clothed dummies with leather and denim showed the serrations only got caught in the fabric, they didn't "rip" through perhaps as expected. Plus, serrations are harder to sharpen, and the entire point of carryng a knife is to carry a SHARP knife, which means regular sharpening. My first carry knife was a Benchmade Mini AFCK with a half-and-half Black Ti blade. After the tip broke off fixing my mother-in-law's kitchen cabinet, I bought a full-sized AFCK with a plain blade. That being said, for household chores, serrations will cut through cardboard or twine easier than a dull plain blade. But both perform equally well when sharp, IMHO.
 
My Spyderco does double duty as a work knife and defense knife if needed. The serrated blade functions better in the applications I use the knife.
 
1. I'm not an expert.

2. www.bladeforums.com ... 'nuff said.

3. Serrations work best when sawing through fibrous material. So if you do a lot of sawing-type cutting of stuff like rope, wood, vegetation or fabric, serrations are definate plus.

4. Serrations do not work well at all for push-cutting, which is what most cutting tasks are, especially most precision/delicate cutting tasks.

5. Most part-serrated knives do not have a long enough serrated section to devlop a good cutting stroke...so whats the point?

6. Most (all?) part-serrated knives have the serrated portion closest to the grip...just where you would want the non-serrated portion if you were going to do very fine, detailed cutting. So, again, whats the point?

7. Serrations are a biotch to sharpen.

I own a few knives. Only one is part-serrated, and only one is fully serrated. I'm not a big fan of serrations.

Mike
 
I carry mine for cutting through seatbelts in case of a wreck, plane crash, (before 9-11) and other such problems.
 
I carry a Cold Steel "Gunsite" folder, which is half serrated tanto point. For "push cutting" I tend to use the steeply inclined forward edge, for "pull cutting" the forward (plain) part of the lower edge, and for fibrous material the serrated part.

The serrated part does tend to hold the edge longer, although some of the serrations have been worked out of the knife. I usually sharpen with a tri-angle sharpener (I forget the brand name) and just go over both parts of the blade the same way. Unless I have a lot of time, then I sharpen the serrations as well.
 
Like Coronach's #3...

Plain blade - summer
Serrated - winter (usually better to cut through heavy winter clothing)

:cool:
 
I did a defensive knife class and the instructor recommended serated blades for defensive purposes. He indicated, and was backed up by a couple of paramedics that were there, that the jagged serated cut will bleed out faster that a precise clean cut from a plain edge. A very clean linear cut wants to re-seal itself and localized swelling can push the two halves of the cut together. The serrations turn the matching process into a jiggsaw puzzle.

However, like most others I dont like trying to resharpen the serated and the plan edge is more functional for a variety of every day tasks so I carry a really really sharp plain edged knife.
 
I had a job that required cutting through a lot of plastic wrap and schrink wrap coatings. The wrap would bind up, making the straight edge almost worthless. For a while I started carrying 2 knives, one fully serrated, the other straight edge only. Later on I did the compromise thing and got a 1/2 and 1/2.
 
Just as a side note, there's a passage in "All Quiet On the Western Front" where the narrator advises a newcomer not to use a serrated or sawtooth bayonet blade because of what will happen if the other side catches him carrying such a blade. The author served (and was killed) in WWI, so he probably knew of what he spoke. Serrated blades must have had at least some psycological effect.

I took a defensive folding knife course and the instructor advised against serrated blades saying, "No other culture in history [many of which were far more blade-dependent than we are today] ever saw the need for a serrated blade." Whether that's true or not, I dunno. Just FYI. I carry a half-and-half Spyderco myself, I would not want one that's fully serrated.
 
The lesson shown to me...

I'll preface this by saying that I don't particularly like serrations, I think they're a pain to make, a pain to sharpen, and only useful in about a quarter of the tasks a knife might be called on to do.

That said, I did have the 'point' of serrations (pun intended, apology tendered) explained quite graphically to me. It was done thusly:

My friend Eric was very into cutting and testing everything he made or used. He had therefore had ample opportunity to try various blade designs. His simplest cutting test was to hang a two-litre bottle, filled with water, from a rope. This, while by no means a realistic test, offered a reactive target, which simulated a medium/hard cutting situation.

He had me take my best shot it, using a plain blade. Several of my best shots, in fact. To my embarassment, I couldn't even penetrate the bottle. I would have had more effect if I'd used a hammer. The bottle was scratched, and swung wildly, but not cut through. I was mortally embarassed, until explained a couple of things to me, and I tried a couple of other knives. A knife, he explained, will slash soft tissue, given enough resistance. Against a target that will roll or shift, however, a straight edge is as likely to slide harmlessly off as to penetrate. To heighten the possibility of penetration, he further stated, there has to be some abrupt change in the edge geometry. This he demonstrated with a 'Tanto' tip--you know, that sharply angled tip style so lately all the rage with Tactical knifemakers. It easily laid the bottle open, given a similar slash from me. Serrations, then, he offered, are simply nothing but smaller and frequently repeated changes in the edge geometry, to allow the force of the blade to be focused on an extremely small point, thus overcoming the resiliency of the target, and its natural tendency to shift or roll. Continuing tests with a Spyderco seemed to bear this hypothesis out.

Another example might be to take a tomato. Try cutting it with an edge that has been highly honed and polished smooth. You may find it surprisingly aggravating. Certainly, once the skin is pierced, the remainder of the cut will be effortless. But piercing it initially may give you problems, unless you either cheat and use the point, or have an extremely firm tomato, to begin with.

Finally, having worked in theatre as a flyman and a rigger, I have found that serrated knives are all but useless for cutting hemp rope. The teeth tend to catch in the fibres, but unless you can steady the rope and saw away at it, you'd be better off with a plain edge. Alternately, you might see surprising success with the very shallow, wavey serrations on the average breadknife. I've seen them used by guys hanging upside down, 50' above a stage floor, where there was no other option but to cut it, the first time, with one hand.

My two coppers...

:D
 
Comment on the hanging water filled soda bottle test.

I've trained in a martial art that used that for practice with knives.

It gets easier with practice. Hardly anyone can do it repeatedly when they first start even with pull cut type slashes. Push cut type slashes are even more difficult for beginners.

It also gets easier with larger blades. May be a lesson here: use enough knife!:)

I can't do it repeatedly but I know people who can cut reliably against the hanging soda bottle both pull cut and push cut from the eight basic directions: horizontal, reverse horizontal, vertical from above and below, and the four oblique angles. A few of the guys that I've seen can cut the bottle in two using a blade that is barely longer than the diameter of the bottle
 
I have heard the same thing as Bullwinkle did in his class.
My friend who teaches a lot of different LEO types says
the serrated cut is much harder to close up and bleeds more.
Just what i've heard, no personal experience. I carry an Emerson commander, half serrated myself.
 
Perhaps I should browse this particular forum more often, as you folks have some really interesting topics ...

Regarding "plain" versus serrated edges of "small" blades ... meaning under 12", or so ...

Several years ago I came to the surprsing ... to me ... realization that the newer serrated blades seemed to be more "effective" employed against different mediums in different circumstances.

Some cloth, fiber and plastic or elastic materials, depending on thickness, elasticity and tension, seemed to be cut more easily by the newer serrated edge technologies. Interesting, and very useful for my L/E job. A better tool for cutting. Plain & simple. Not a weapon, meaning primarily intended to be an "offensive" weapon, but as a tool.

Then ...

Some of the newer ... including updated "older" ... designs seemed to offer better potential for defensive applications, as well.

Not all, but many, of the newer serrated edge designs offered increased effectiveness when it came to cutting flexible and elastic materials such as skin, cloth and leather. This increased effectiveness was most noticeable when it came to glancing contact. As previously stated, the smaller points and angled "edges" of the serrated cutting designs simply caught and cut more often in circumstances where plain edges often wouldn't ... at least, not as often or as deeply.

Serrations do, indeed, hang up and get caught on things. This may cause the blade to bind, or at least lose its momentum, as it were ...

The proper tool for the proper job.

I seldom cut anything with those blades I carry for anticipated defensive circumstances. Resharpening the serrations on those blades isn't a consideration or concern, as the only way they'll ever become dulled or damaged is by actual use in their intended application. I carry other blades for other mundane cutting puposes. This requires I often carry more than one blade. So be it.

Not all of my defensive blades are serrated, and not all of them are "plain" edged ... some are even "combination" edged, which is a compromise, of course. But small blades are a compromise by their very nature, so it's all a matter of risk assessment and personal determination in the final analysis.

I feel less than comfortable wearing a fixed blade while riding my motorcycles, for what it's worth ... ;) Folders are useful as a compromise for a variety or reasons ... :D

Great thread and posts, gang ...
 
im not going to out-and-out disagree w/ bulwinkle and psssniper b/c i think they probably know more than i.
that said, i accidently cut a dog fairly severely while trying to remove some matted hair w/ my comboedge BM 710. the vet said the cut was very easy to close b/c the laceration was clean (read: not jagged). the serrated part of the knife did the cutting.
just my experience.
 
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