Folding knife size efficiency

Sergiusz Mitin · Aug 12, 2000

<center>Folding knife size efficiency.</center>

The knife is the tool for cutting and we do it with the edge. The blade holds the edge, the handle holds the blade. In case of a folding knife the handle has also another purpose, it has to accommodate the blade in closed position. Naturally it should be longer than the blade, the question is just how much longer? In another words, how large part of opened folding knife makes up the blade and how large part of the blade makes up the edge? In my opinion these parameters are pretty important to evaluate knife design quality. Of course their importance shouldn't be overrated and taken as the main or especially the single criteria choosing a knife...
For long time I was curious to compare size efficiency of some folding knives made by top-notched knife manufacturers. It is difficult or even impossible to do it looking onto factory specifications because manufacturers are applying quite different methods to measure for ex. blade length. So I decided to compare them measuring all knives according the same method.
For my review I selected some knives which I have or I had an opportunity to measure by myself. I excluded from this review the knives with manufacturer declared blade length less than 3" because the small knife designs quite frequently are influenced with somewhat another reasons, for ex. handle's minimal dimensions for secure grip etc. Here I also noticed some funny phenomenon and had to make some exclusions. For ex. SPYDERCO Delica's blade length is declared as 74 mm (less than 3") but really it is noticeably longer. On the other hand, Katz Knives Black Cat Ltw. has claimed blade length 3 inches but really it has shorter blade. I also excluded knives there the proper grip places user's finger(s) directly onto the blade, like in the SPYDERCO Calypso Jr. In this case the whole my measuring method would be wrong because the part of the blade in fact serves as handle.

<a href="http://albums.photopoint.com/j/View?u=222944&a=2716881&p=25604201&Sequence=0" target="_blank"><IMG align=right SRC="http://albums.photopoint.com/j/View?u=222944&a=2716881&p=25604204&Sequence=0" border="3"></a>The opened knife overall length (parameter A) I have measured between two the most distant points on the knife body.
The blade length (parameter B) I have measured as how deeply the blade can be plunged into the target. In another words this is the distance between the blade tip and the most protruding handle's point in plunging direction. Sometimes it caused curious results, the BENCHMADE Model 730 Ares blade length and as result size efficiency was noticeably affected with handle's hump forwards near blade spine. If I would measure blade length along point-pivot axis the ratio would be much more favorable. This displays that my measuring method maybe is not the best for all knives but I had to choose one and to measure all knives according the same.
The edge length (parameter C) I have measured along the edge which is really able to cut, following all it's curves and recurves (of course excluding serration curves). Tanto blade edges were measured including fore-edge. So please do not be surprised with the fact that some knives may have edge with the same length as the blade or even longer.
I have rounded up all measurements to whole millimeters and all calculated results to two decimal places. Think this precision grade is quite enough for practical use. I have used knife weight data from manufacturer specifications because I have not enough precise balance at my home. I couldn't found weight factory data for few knives only, so I have weighted them in the nearest food shop. These data are marked with asterisks.

Here are results:
<center><table border="1" cellpadding="2" cellspacing="1"><tr><td valign="top">Manufacturer </td><td valign="top">Model</td> <td align="center" valign="top">Weight, grams </td><td align="center" valign="top">Overall length, mm </td><td align="center" valign="top">Blade length, mm </td><td align="center" valign="top">Edge length, mm</td> <td align="center" valign="top">Blade efficiency </td><td align="center" valign="top">Edge efficiency </td></tr><tr><td> </td> <td> </td><td align="center">Factory spec. </td><td align="center">A </td><td align="center">B </td><td align="center">C </td><td align="center">B/A </td><td align="center">C/B </td></tr><tr><td>Benchmade</td> <td>710 Axis Lock</td><td align="center">128 </td><td align="center">228 </td><td align="center">102 </td><td align="center">102 </td><td align="center">0,45 </td><td align="center">1,00 </td></tr><tr><td>Benchmade</td> <td>730 Ares</td><td align="center">125 </td><td align="center">208 </td><td align="center">88 </td><td align="center">88 </td><td align="center">0,42 </td><td align="center">1,00 </td></tr><tr><td>Benchmade</td><td>750 Pinnacle</td> <td align="center">125 </td><td align="center">212 </td><td align="center">93</td> <td align="center">94</td> <td align="center">0,44 </td><td align="center">1,01 </td></tr><tr><td>Benchmade</td> <td>800 AFCK</td><td align="center">116 </td><td align="center">235 </td><td align="center">101 </td><td align="center">100</td> <td align="center">0,43</td> <td align="center">0,99 </td></tr> <tr><td>Benchmade</td> <td>910 Stryker</td><td align="center">108 </td><td align="center">208 </td><td align="center">92 </td><td align="center">88</td> <td align="center">0,44</td> <td align="center">0,96 </td></tr> <tr><td>Böker</td> <td>Walter Brend Tactical</td><td align="center">170 </td><td align="center">225 </td> <td align="center">97 </td> <td align="center">96 </td> <td align="center">0,43 </td> <td align="center">0,99 </td> </tr> <tr> <td>Böker</td> <td>Gemini</td> <td align="center">90</td><td align="center">208 </td> <td align="center">88</td><td align="center"> 90</td> <td align="center">0,42 </td> <td align="center">1,02 </td></tr><tr> <td>CRKT</td> <td>M16-01 CF</td> <td align="center">45 </td><td align="center">182 </td><td align="center">81 </td> <td align="center">79 </td><td align="center">0,45</td> <td align="center">0,98 </td></tr><tr><td>CRKT</td> <td>Mirage Gray Ghost</td> <td align="center">145 </td><td align="center">200 </td><td align="center">90</td> <td align="center">90 </td><td align="center">0,45 </td><td align="center">1,00 </td></tr><tr><td>CRKT</td> <td>Point Guard</td> <td align="center">116 </td><td align="center">209 </td><td align="center">90 </td><td align="center">86</td> <td align="center">0,43 </td><td align="center">0,96 </td></tr><tr><td>Ka-Bar</td> <td>D2 Extreme Tanto</td><td align="center">85 * </td><td align="center">191 </td><td align="center">76 </td><td align="center">75</td><td align="center">0,40 </td><td align="center">0,99 </td></tr><tr><td>Katz Knives</td> <td>Black Cat Ltw.</td> <td align="center">60 * </td><td align="center">172 </td><td align="center">72 </td><td align="center">68 </td> <td align="center">0,42 </td><td align="center">0,94 </td></tr><tr><td>Katz Knives</td> <td>Special Forces</td> <td align="center">155 * </td><td align="center">227 </td><td align="center">97 </td><td align="center">90 </td><td align="center">0,43 </td><td align="center">0,93 </td></tr><tr><td>Kershaw</td> <td>Avalanche </td> <td align="center">100 * </td><td align="center">192 </td><td align="center">82 </td><td align="center">82 </td><td align="center">0,43 </td><td align="center">1,00 </td></tr><tr><td>Kershaw</td> <td>Boa</td> <td align="center">140 * </td><td align="center">205 </td><td align="center">87 </td><td align="center">83 </td><td align="center">0,42 </td><td align="center">0,95 </td></tr><tr><td>Kershaw</td> <td>Ricochet</td> <td align="center">91 </td><td align="center">192 </td><td align="center">82</td><td align="center">81 </td><td align="center">0,43 </td><td align="center">0,99 </td></tr><tr> <td>Kershaw</td> <td>Ti-Hawk</td> <td align="center">85 </td><td align="center">196 </td><td align="center">85 </td><td align="center">79 </td><td align="center">0,43 </td><td align="center">0,93 </td></tr><tr> <td>Puma</td> <td>Advantec</td> <td align="center">140 </td><td align="center">189 </td><td align="center">77 </td> <td align="center">76 </td> <td align="center">0,41 </td><td align="center">0,99 </td></tr> <tr> <td>SOG</td> <td>Pentagon Elite</td> <td align="center">94 </td> <td align="center">219 </td> <td align="center">101 </td> <td align="center">94 </td> <td align="center">0,46 </td> <td align="center">0,93 </td> </tr><tr><td>SOG</td> <td>Jet Edge 2</td> <td align="center">99 </td> <td align="center">217 </td> <td align="center">96 </td> <td align="center">96 </td> <td align="center">0,44 </td> <td align="center">1,00 </td></tr> <tr><td>SOG</td> <td>Night Vision</td> <td align="center">113 </td> <td align="center">211 </td> <td align="center">95 </td> <td align="center">94 </td> <td align="center">0,45 </td> <td align="center">0,99 </td></tr><tr> <td>Spyderco</td> <td>C11 Delica</td> <td align="center">54 </td> <td align="center">178 </td> <td align="center">79 </td> <td align="center">71 </td> <td align="center">0,44 </td> <td align="center">0,90 </td> </tr><tr> <td>Spyderco</td> <td>C36 Military</td> <td align="center">113 </td> <td align="center">244 </td> <td align="center">104 </td> <td align="center">97 </td> <td align="center">0,43 </td> <td align="center">0,93 </td></tr><tr> <td>Spyderco</td> <td>C48 Tim Wegner</td> <td align="center">172 </td> <td align="center">213 </td> <td align="center">94 </td> <td align="center">89 </td> <td align="center">0,44 </td> <td align="center">0,95 </td></tr><tr> <td>Spyderco</td> <td>C55 Starmate</td> <td align="center">120 </td> <td align="center">220 </td> <td align="center">96 </td> <td align="center">94 </td> <td align="center">0,44 </td> <td align="center">0,98 </td></tr><tr> <td>Timberline</td> <td>Special Service</td> <td align="center">170 </td> <td align="center">217 </td> <td align="center">97 </td> <td align="center">88 </td> <td align="center">0,45 </td> <td align="center">0,91 </td></tr></table></center>

Using these measurements someone could calculate some another ratio if he or she would like, for ex. blade to handle or edge to overall knife length ratio and so on.

Conclusions? They are sometimes funny, sometimes surprising, but how useful they are - let each of us decide for himself. I personally was surprised that my favorite in blade-to-overall-length ratio, BM 710 Axis Lock has, sure, very high ratio but not the highest. The same ratio have pretty many another knives. Unlike quite common opinion Military has not worse ratio than AFCK. Pinnacle and Böker Gemini have the edges longer than the blades. And so on...

As I already specified, these parameters may be interesting but no way are essential for knife choice. In any rate knowing them I personally didn't change any my preference or liking...

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Sergiusz Mitin
gunwriter
Lodz, Poland

[This message has been edited by Sergiusz Mitin (edited 08-12-2000).]

Esav Benyamin · Aug 12, 2000

I don't know if the ratio of blade to handle is always important. My Vaquero Grande with a handle of some 7" is much longer than my hand needs it to be, but this allows a difference in grip, from choked up for more control, to farther back for more reach in slashing. The Sifu does the same thing rather explicitly by putting more finger grooves than most of us have fingers!

I think an interesting ratio among otherwise similar knives would be the weight per length of blade edge: how much mass do we lug around for how much cutting ability.

cerulean · Aug 12, 2000

Thanks for the interesting information, Sergiusz.

I've always thought it's weird that some people care a lot about the blade to handle ratio. Certain people even go as far as saying that a knife's design is bad simply because the handle is considerably larger than the blade!

Keep in mind that two of the most important edged tools and weapons throughout history have been the spear and the axe. Both play a far more vital role in the history of human beings than the sword, although the sword is more romantic.

The sword has a great handle to blade ratio and, of course, the spear and axe both have a horrible ratio (the handle can easily be 10x longer than the blade). However, it seems pretty silly to call an axe or spear "inefficient". That term seems to be used only with folding knives.

When people look at the folding knife design, for some reason they want to imploy engineering principles that are purely aesthetic. They don't want there to be "wasted space" in the handle. However, it must be noted that there is only wasted space in the handle when the knife is closed and not in use. It seems like we should be more concerned about what the knife does when it's open, and when it's open there isn't any wasted space.

Another thing to consider is that here in the US there are many laws restricting the blade length on knives. One way to compensate for these laws is to simply have a longer handled knife. The extra handle length can provide additional reach, penetration, and leverage.

David Rock · Aug 12, 2000

For ex. SPYDERCO Delica's blade length is declared as 74 mm (less than 3") but really it is noticeably longer.

I'll bet I know why. When the Delica and Endura were were updated in 1998 the handles came out a bit longer than in the originals, presumably to accomodate the reversible clip attachment screw. With a slightly longer handle it became possible to increase the blade length a bit as well.

David Rock

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AKTI Member # A000846
Stop when you get to bone.

Folding knife size efficiency

Sergiusz Mitin

Esav Benyamin

MidniteSuperMod

cerulean

David Rock