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View Full Version : Why serrated edge blades?


yankytrash
August 28, 2002, 05:33 PM
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?

OF
August 28, 2002, 06:04 PM
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

Guy
August 28, 2002, 06:05 PM
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.

LBC
August 28, 2002, 09:15 PM
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.

Hkmp5sd
August 28, 2002, 11:03 PM
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.

Coronach
August 28, 2002, 11:45 PM
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

Reloader
August 29, 2002, 07:07 PM
I carry mine for cutting through seatbelts in case of a wreck, plane crash, (before 9-11) and other such problems.

Gunter
August 30, 2002, 11:45 AM
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.

vitiaz
August 30, 2002, 12:34 PM
Like Coronach's #3...

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

:cool:

Bullwinkle
August 30, 2002, 02:03 PM
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.

gryphon
September 2, 2002, 08:53 AM
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.

Drjones
September 4, 2002, 12:44 PM
Why not???

Personally, I think they look cooler than plain edges, and they come in handy for tougher jobs.

MK11
September 4, 2002, 01:48 PM
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.

Kalindras
September 4, 2002, 03:37 PM
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

Byron Quick
September 4, 2002, 10:40 PM
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

psssniper
September 4, 2002, 11:51 PM
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.

fastbolt
September 9, 2002, 04:25 PM
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 ...

Oleg Volk
September 9, 2002, 07:03 PM
The author served (and was killed) in WWI,

Remarque wasn't killed in WW1 -- his character in the book did.

notos&w
September 11, 2002, 09:11 PM
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.

Ewok_Guy
September 13, 2002, 11:55 PM
The only serrated blades I use are in the kitchen.

clown714
September 14, 2002, 07:25 AM
i,have yet to come across a situation,

where my fully serrated military spydie did not perform:)

clown

OutLaw
September 18, 2002, 07:23 PM
I like a plain blade,I have no use for serrations.

Gomez
September 19, 2002, 09:16 AM
I've never cared for partially serratted blades on carry knives. They seem to be a compromise that failed.

From the 1996 Spyderco catalogue, "Serrations work especially well for agressive jobs such as cutting rope, seat belts, cardboard, rubber hose and leather. ...Plain edges generally perform best for chores like wood cutting, fileting and caping."

All things being equal, a serrated edge will cut longer after it begins to dull than a plain edge and it will gain between 10% and 30% more cutting surface. Conversely, plain edges are eaiser to sharpen, they are legal in more jurisdictions and they look less "menacing" than serrated knives in the eyes of most people.

I believe that a knife carried for defensive applications must be kept razor-sharp and not used for daily chores. I carry a Leatherman SideClip and a Micra in addition to my defensive knives. Those are the blades that get used and abused through daily use. I carry my Leatherman Micra on a splitring with an ARC light. The ARC light is my daily lightsource, thereby saving the batteries in my defensive SureFire E2e and the Micra is my daily tasks knife, saving the edges on my defensive knives.

Gomez

pbarrick
September 19, 2002, 04:57 PM
If you're carrying a defensive knife, I think that you are better served by a plain-edge than a serrated one. Plain-edges tend to cut through clothing without the tendency to catch that serrated knives display.

It also comes down to the question of why you carry a knife. If it's for defense, use if for that task only to keep it as sharp as you can for when it's needed in that role. If it's a daily-use knife, use whatever you like.

If you need both a defensive knife and a daily-use knife--carry two. They're small, cheap and easy to come by...

That being said, a friend of mine often purchases combination edge knives. His stated use for a half-serrated, half-plain edge? He trims his fingernails with the serrations...

hso
September 21, 2002, 07:38 AM
My personal exsperience is that for most materails a factory serrated, either spyderedge or bechmade, edge will cut through faster than a factory plain edged. I have cut natural fiber, nylon and kevlar strap and line with both and have found the serrated edge to perform better and more consistantly.

My first experience that convinced me of this was with a 4 inch kevlar strap that had been used as a tow line to pull a heavy truck from the mud. The guys had knotted it around the bumper of a mobile drill rig and it was well and truely locked in place after hauling the thing up slope at a hazardous/radioactive waste site. The field manager and I watched these guys hacking and sawing at the strap with a variety of pocket knives (and these boys kept their Case and Buck folders sharp as razors) to no avail. Knowing that I carried more than one knife at any time he looks at me and the following exchange takes place, "They need a knife." "They got knives." "They need a SHARP knife." "Sigh". I squitch-thump downhill, did I forget that it had been and was raining at the time and that I was on a cane from having my ACL replaced, and after a brief and somewhat vulgar explanation from the driller he yanks the strap taught and gives me the "Ok techie puke, let's see what ya got" look. I pulled the Spyderco serrated Delica from my pocket, opened it one handed and cut the strap with one stroke. His, and his crew's, plain edges had been skipping off the strap fibers, but the serrated edge popped them like they were nothing. After that I almost had to buy another knife for them because they kept borrowing mine. I've repeated this with large and small lines and webbing of different materials over and over again.

I have not needed to "saw" with serrated edges, but I have had to take more than one pass at times for very thick materials. Sawing isn't needed and the back and forth motion subjects the user to the risk of cutting themselves. (For those of you that think that only an incompetent would cut themselves this way just remember the serrations are not teeth on a saw and anytime you push towards a blade you risk your warm tender pink parts being rudely introduced to the blade's cold hard silvery parts.)

If you carry a kife for defensive purposes you should never use this knife for other things. It should be left as sharp as you can possibly get it so that should it be needed to save your life it works a well as possible. Carry a second utility knife for the strap cutting, apple peeling, fingernail cleaning and leave the weapon of choice ready for it's purpose. This also gives you an excuse to have more knives, which is always a good thing in my mind!

BamBam-31
September 26, 2002, 04:11 AM
Just my two cents:

While playing with my Benchmade AFCK, I managed to slice my finger with the serrated section. Jagged cut, bled profusely for half an hour despite pressure and elevation. Nasty.

I'd hate to be actually wounded in a knife fight by any kind of blade, but if given a choice, I'd rather be cut with a straight edge.

As mentioned earlier, the combo blade is a compromise. Some of us don't live by HK's motto. I'm sure it'll do what I'll need it to do should the need arise.

M1911
September 26, 2002, 12:20 PM
I only carry one knife, and use it for general duty. I used to carry a sypderco delica with a full serated edge. I found that it cut very easily and stayed sharp much longer. It wasn't good at cutting paper -- it would mostly tear rather than give a nice cut. Unfortunately, once dull, it was very hard sharpen.

These days I carry a delica with a plain edge. It doesn't stay sharp as long, but it's quite easy to sharpen.

M1911

pbarrick
September 26, 2002, 12:31 PM
Actually, serrated wounds tend to close on their own because of the way the serrations tear through flesh. A plain-edge actually leaves a wound that doesn't close as well (on it's own, that is).

I tend to carry a defensive blade and save it for that purpose only. I use a secondary blade for general cutting tasks.