First Case/Ruple collaboration officially debuts at BLADE Show ’24.
The combination of mechanical features, artistic design and choice of handle materials make the Bill Ruple x Case Axe Handle collaboration a unique knife for the user and collector.
Case Knives and BLADE Magazine Cutlery Hall-of-Fame® member Bill Ruple didn’t just bump into each other at the convenience store one day and say, “Hey, let’s do a knife collaboration.” That alone likely would have led to a great pocketknife, but no, there was a lot more planning and history that went into this new joint venture. We’ll talk about some of that but first let’s talk about the knife itself. It’s got some special character.
Case Axe Handle Design
Despite both being giants in the slipjoint field, Bill and Case sifted through some ideas and came up with a lockback pattern for an initial collaboration. It was not just one part but several features Bill combined together to make this knife unique.
Preeminent member of the Texas Slip Joint Cartel, Ruple more than understands what makes a good slippy.
As a man who had farmed the soil, he noted the end of the knife resembled the shape of an axe handle, thus the name. The upward curve of the handle butt provides some useful ergonomics but also strategically holds the tail of the lockbar. In this location, there is resistance to accidental unlocking of the blade while it’s in the open position. As well, it eliminates the need for a thumb cutout in the handle to release the blade. With an upward curve partially concealing the lockbar plus the absence of a thumb cutout, the handle makes the knife appear not to be a lockback pattern at all. In fact, since at first glance it seems to be a slipjoint, it has a bit of the trick-knife or mystery-lock character.
Initial prototyping by Bill in his shop hit a snag in that the slipjoint knives he’s used to creating have a rear bolster. That did not fit the artistic design for the new collaboration. However, Bill cleverly overcame the so-called snag by using a feature called a scissor spring (see illustration, page 40), which rests on a bushing to provide the needed tension to work the lockbar. Bill has prototyped knives for Case and also assisted with some aspects of manufacturing just as his Case collaboration predecessor, mentor, very close friend and fellow Cutlery Hall of Famer, Tony Bose, had done. Bill stated that nobody could replace Tony Bose and Case misses him. (Don’t be at all surprised if Case makes a commemorative knife in honor of Tony in the future.)
A few notes on Ruple’s design, the scissor spring (rear top right) is an efficient use of space with a one-piece unit of lockbar and spring. The bushing (lower fork of the spring), the spring rides on this avoiding excessive wear and taking up less room. It also acts as a rear spacer.
Both Case officials and Bill say Tony would be pleased with the new collaborative effort. The initial run will be 1,000 knives. Then the model will be made in a traditional slipjoint pattern. There is an aim at “near custom maker quality” for the first run, glibly naming the process “almost custom,” beginning with the parts being wire cut. That’s the cool way to say electrical discharge machining, or EDM. Production is assigned to a specific group of three workers only. No one else will work on the knives. That sort of consistency helps maintain quality control in manufacturing the knives.
MORE TO COME Is this collaboration just an outlier or will there be more Case/Ruple lockbacks in the future? Interest in the knife at BLADE Show 2024 (page 26), where the knife was officially introduced, was quite favorable. Both Bill and Case officials were pleased with how things have turned out, so expect to see another collaboration introduced at next year’s BLADE Show. That knife likely will be a slipjoint. Another lockback might be seen in the future, though a bit further down the road.
Natural birdseye maple is one of but several handle material options on the new Bill Ruple x Case Axe Handle.
As collaborative efforts go between manufacturer and custom maker, the Axe Handle knife is a superlative effort. And there is strong motivation to produce more collaborations, both commemorative and unique.
Ruple’s First Case
Does BLADE Magazine Cutlery Hall-of-Fame® member Bill Ruple remember his first Case knife? Is Texas big?
“Oh yeah,” the good-natured, award-winning knifemaker and South Texas Slipjoint Cartel trail boss said. “My dad gave me a Case knife when I was 9 or 10 years old, and it was a yellow handle Case trapper. And man, in about a month I had sharpened the blades completely out of that knife. And he gave me another one, and so he told me not to sharpen it quite as often. But yeah, a long time ago.”
Case Axe Handle Specs Knife type: Lockback Designer: BLADE Magazine Cutlery Hall-of-Fame® member Bill Ruple Blade length: 3.46” Blade material options: Wire-cut 154CM stainless steel or damascus Rockwell hardness: 57-59 HRC Blade grind: Flat taper Blade @ thickest: .126” Blade pattern: Clip point Blade finish: Satin Handle material options: Natural birdseye maple, Rogers jig chestnut bone, standard jig antique bone, marbled black carbon fiber, abalone, English walnut Lock: Lockback Opener: Nail nick Pocket clip: None Weight: 4.21 ozs. Closed length: 4.4” Carry: Suede leather taco pouch Special features: One-piece designed backspring & lock mechanism. Country of origin: USA MSRP: $599.99 to $774.99 Available: Late Summer 2024
Design factors are crucial in matching the knife handle and the hand.
It all started with a stone. Held between the thumb and index finger, it could be used to cut things efficiently if the user learned how to keep the edge sharp. It was the birth of knife technology.
The next step was to attach the stone to a stick. The stick handle afforded more versatility on how the stone blade could be used. Even though it started out looking like a mere piece of broomstick, there is some obvious utility in it since many knives today have the same simple shape. As a result, though knife handle technology did advance quickly at first, it really hasn’t changed that much in several thousand years. The reason is hand ergonomics. There are only so many ways a handle can fit into the human hand, though small differences in handle design can sometimes be profoundly important.
Asymmetric handles can improve grip but also limit versatility. An example is the karambit. The handle of the Elite Enforcer from Brous Blades is designed to provide a reliable grip in forward or reverse tactical positions. (Brous Blades image)
I bet that, as a knife collector, you have handled hundreds of knives and often exclaimed, “This knife is perfect.” We all have. What did we mean? What were we thinking? I would also bet the knife handle fit very snugly in your hand when you thought that. You were able to get a firm grip while you envisioned yourself using the knife on a camping trip, or perhaps defending your life, or doing a multitude of different tasks. The handle wasn’t too big, nor too little. There were no pressure points or sharp contours that caused discomfort. Your approval of the handle was probably appropriate to the task you were contemplating. However, while all blade configurations are not well suited for every possible task, likewise, for best use the knife handle design must complement the blade to which it is attached.
Cutting Jobs
Let’s simplify knife tasks into four basic categories:
First are the simple everyday cutting chores, better known as “everyday carry” stuff. Open a package, cut a string, peel an apple, it’s just EDC. You think any tool with a sharp edge will do—and you’re right;
Second is where you must open 500 cardboard boxes or a similar job that takes some degree of force and puts a lot of stress on your hand;
Third is where you slice 10,000 tomatoes. Well, private, that’s a rough eight-hour shift in the mess hall! Many kitchen knives have some very non-ergonomic handles. Not a big deal if you’re cutting just one tomato, but in eight hours of doing that your hand might actually get some permanent damage. Yes, permanent;
Fourth is an oft-used example and the pinnacle of all scenarios: defending your life. Oh yes, there has been many a knife made for extreme situations. It’s fun to own a big bowie!
The perfect handle for an EDC has so much latitude that the word perfect doesn’t seem like it should ever be used. Going to the other extreme of the fourth category, the concern would be on grip strength. You would not want to lose hold of the knife during a life-or-death situation. A handle that provides a good grip probably would sacrifice some versatility, though in an extreme situation grip strength is probably more important than versatility.
Size
Is the size of the handle’s diameter really important? There is some leeway here, but once you get into endless tomato and box cutting and especially the need for maximum “grip strength” during life-and-death situations, it is a very important factor. According to many studies, as the handle diameter is progressively increased, so too is the grip strength—at least up to a certain point. After that, grip strength starts to decrease.
It is a bit odd that shoe sizes come in a variety of lengths, even half sizes, and also various widths, but gloves are basically small, medium, large and extra large. Why not size gloves more like shoes? The expression “fits like a glove” might mean you are lucky to find a pair that actually fits.
Does one size fit all? Yes, sometimes. But just like buying shoes, you have to put them on and walk around the store a while. If you plan to climb a mountain, you better be damn sure that the shoes will fit, perform and not cause blisters. If a knife handle feels good, then is it good? Probably so. There are many knife handles that “look good” but the proof is how they feel in your hand, your particular hand.
Knife Handle Diameter
Gripping round sticks/knife handles of different diameters results in different ergonomic effects.
The first example shows less than optimal grip strength with a thin handle having diminished contact area between the palm and the handle surface. The force is maximum when the thumb and fingertips are directed parallel to the palm.
The second example favors a strong grip. The fingers are also able to wrap around the handle and there is more surface contact available.
The third example is near the peak of biomechanical advantage. Grip strength might be a little improved from the second example or perhaps a little diminished. Not very different there. Importantly, the thumb and fingers can still cross over each other. There is more advantage from friction. This might be the best fit for a baseball bat. Yet for a knife there will be less ability to change the hand position, which may be a disadvantage. Some consider a diameter of about 1.5 inches to offer the strongest grip and this example is a little larger than that.
The fourth example is loss of grip strength. The fingers can’t encase the handle. The strong ergonomic “power grip” is transforming to the ergonomically weaker “pinch grip.” —by LeRoi Price
Hand vs Handle
We already know about handle diameter. What about shape? Though the round shape of a broom handle works for a knife handle, an oval configuration fits well into the hand and, importantly, allows for indexing of the blade’s cutting edge. Most knife handles have a basically oval cross section.
Form follows function but it begins with ergonomics. There are several dedicated handle configurations that are suited well to a special purpose but are mainly limited to use for that single special purpose. One of the most notable examples is the karambit handle. Asymmetric handles can improve the grip but also limit versatility.
The anatomy, ergonomics and biomechanics of the hand present some challenges for handle design.
Palm Anatomy
Prominent features of palm anatomy play a pivotal role in hand ergonomics. The red line is the actual bending point of the fingers. The blue dots are where the fingers bend from the palm. The green dashes are the second of the three bending points of the fingers. The yellow squares represent the prominence of the base of the thumb. The black hyphens indicate the small prominence of the heal of the hand. The oval of white squares is a hollow space in the center of the palm.
Note: the hand is not like a door hinge. These lines move as the hand goes from flat open to a closed fist. Now look at the back of your hand as it goes from open to a fist. The knuckles go from a fairly flat line to a downward curve. The finger joints all have a different radius at which they bend. Hand ergonomics is not a static condition, which makes things difficult for handle design.
Handle Subtlies
Here is a simple camp knife and somebody made it right. I’ll point out my reasons why starting with the finger groove (B). It is well demarcated though not deep nor very pronounced—just like all the subtle features of this handle. This allows the handle to be more easily manipulated than if the fingers are forced into deep recesses. The groove fits the index finger.
A slight forward rise (A) forms an integral guard. This is an important feature. Some knives like this one have a brass guard in front that is not just mere decoration. A rising protrusion (C) fits into the space of the middle and index fingers. Then it’s down to the groove where the little finger resides (D). Another protrusion (E) captures the little finger and forms a rear guard—again, important for a camp knife.
Area “F” extends more rearward and slopes down to contact the heal of the hand. A slight swell (G) fits into the palm. Some knives are flat in this area but that doesn’t fit hand anatomy well. The handle has a very subtle hollow at “H.” This is where the web of the thumb makes contact, which makes it best to keep it subtle. Area “I” rises slightly here but often is left flat in many knives. This is where you place your thumb when doing some tasks. Putting a guard on the handle spine is less effective than putting one underneath because there are no bones in the thumb web—though slightly rising at “I” is useful.
Conclusion
There is no agreement on the shape of the perfect handle, so you are left with my opinion. On the other hand, you have something to think about and can investigate further. My opinion is this: While there is no such thing as “perfect,” there is still “good enough.” The same can be said for a lot of things.
The handle’s outer contours attempt to nest into the hand’s inner contours. A perfect fit of the handle into the palm would not necessarily make for the so-called perfect handle since there are so many variables, such as the strength a particular finger can generate, the forces the blade will be subjected to during use, wrist angle to the blade, slippery conditions, etc. Non-slip handle texture is a different topic altogether, as well as a spongy outer surface that slightly conforms to the user’s palm.
I shouldn’t give numbers but I know you’re going to be curious about some. For a 5-foot-8-inch man, shoe size 9D which correlates to a large size glove, the handle configuration should be oval with a top-to-bottom dimension of 1.125 inch and 1 inch width. These suggestions are approximate, of course, but are the actual dimensions of the pictured camp knife seen with a handle length of 4.675 inches. (Go up to perhaps 1.5 inches height for a combat knife.) The back of the handle should be convex as well as the lower belly. A shallow groove for the index finger is a good option, and perhaps a second one for the middle finger as well. More finger grooves improve grip strength but are a detriment to the ability to manipulate the knife. They also add pressure points.
Ergonomics in a folder also? Absolutely! A Demko AD20.5 has a protrusion/integral guard between areas “B” and “C” that creates two finger grooves. The extra finger groove as well as the protrusion/integral guard forward of “B” are good ideas in a folder. The features increase grip strength, which is hindered in folder handles since they are thin compared to fixed-blade handles. The front of the handle is not squared off, which provides for a finger groove at “A.”
When you find a knife handle that doesn’t feel right, it is probably not right for you. Nonetheless, finding one that fits your hand “good enough” is probably the best you can do, and all you need to do.
