Heavy Duty Survival Knife.
Shelter craft, chopping, splitting, prying, fire making, woodcraft, hunting, field dressing, food preparation, cutting, slicing and self defense are some of the possible tasks for a survival knife. The design concept is relatively new, originating from twentieth century military aviation. Marble were the first to develop hunting and survival knives but their core business would remain focused on tang rifle sights.
Bo Randall became known as maker of high quality Bowie knives in the 1930's. He was flooded with demand for his #1 after the United States entered WWII. The #1's performance in the field assured steady custom for the next 40 years. Randall's #14 was developed for the Korean War and considered the epitome of a combat survival knife. Often supplemented with a Buck 110, it was prolific among forward operating military personnel in Vietnam. The #14 is the template that current designs are based upon, carbon steel, fixed blade, saber grind, .25" spine, full tang, pointed tip, synthetic grips and multi-position sheath.
BK-2 Design Features
1: High Carbon Steel
Carbon steel has significantly more shock resistance than stainless steel, particularly in freezing temperatures. The original #14 came in O2, a hard tool steel with excellent edge retention. Contemporary mass produced survival knives use 1095 or 1095 Cro-Van. It has adequate edge retention but the softer steel is quicker to sharpen. The edge will roll rather than chip and the blade will bend rather than break. Ultimately, delivering superior durability under extreme use. Unfortunately, current Randall Model 14's are geared toward the collector market and consequently only available in stainless steel.
2: Saber Grind
Flat and saber grinds are common in survival knife design. A flat grind's primary bevel tapers from the blade spine to the edge. A saber grind's primary bevel tapers from the middle of the blade to the edge. While flat grinds have an advantage in slicing and splitting, the saber grind retains more material along the blade, which strengthens against lateral load throughout prying or encountering knots during batoning.
3: Pointed Blade Tip
Drop points and clip points can drill, pick and notch wood. The blade choil permits choking up on the edge, for balanced, controlled carving. Use the inverted point to gut small game via a pinch grip on the spine. Survival knives are biased toward utility but will serve as piercing weapons for hunting and self defense. A Bowie knife is more martially focused. Historically, users inverted the straight edge and slashed with the clip to generate deep wounds on the extremities or neck. Survival knives incorporating clip points don't feature the relatively fragile up swept tip of a Bowie. The profile is more akin to a dagger but usually left blunt to facilitate batoning. Pictured above, the BK-2's drop point tip is extraordinarily robust but laterally tapers, providing satisfactory penetration.
4: Synthetic Handle Scales
Synthetic knife handles are more resistant to chipping, cracking and swelling than natural materials. They can be divided into two basic categories, generic and slightly exotic. Zytel and Grivory are essentially nylon thermoplastic with 66 percent glass fiber reinforcement. It's not exotic but is economical to mold and significantly tougher than wood, wood laminate or Bakelite. Kraton is a soft rubber that provides excellent grip at the expense of durability. Micarta and G10 are composite thermosets. Layers of linen or glass fabric are impregnated with phenolic resin and cured into hard sheets. Subsequent machine fabrication results in an extremely durable, textured handle that provides heat resistance and grip in wet conditions. Rivets are traditionally used to attach knife scales but work loose under chopping or batoning. Bo Randall used screws locked with epoxied micarta plugs. Contemporary survival knives feature exposed handle cap screws, supporting user maintenance and customization. Micarta grips are a popular upgrade from the BK-2's slick black Grivory scales.
5: Blade Length
Squaw and twig fires are preferred in survival situations, chopping and splitting firewood expends valuable energy. However, in very wet conditions, a split wood fire may be necessary. Logs of dead wood with a girth of 2" to 4" are processed into kindling by splitting them in half, exposing dry combustible wood. The blade tip should protrude from the log during the splitting process. This enables the blade to be hammered through the center of the log by a piece of dense green wood. This improvised mallet technique is referred to as batoning. The BK-2's wedge-like cross section excels at this task.
Batoning requires a minimum blade length of 5". Longer blades offer more performance. However, an overall length of 12" is a critical constraint of survival knives, thus a maximum blade length of 7". Any additional length degrades practical carry. Larger tools will be stored behind a seat or in a backpack but have a higher probability of loss. Many pilots found Randall's model 14 attack to be cumbersome in the cockpit. Bo shortened the blade design to 5.5" and designated it the model 15 airman. If logs of a larger girth is all that are available, a 5" blade may be used as a chisel via point first batoning. The BK-2's thick spine and exposed tang pommel support this technique. Point first batoning is also useful for pulling chunks of fat wood from pine logs, assisting ignition in wet or humid conditions. Alternatively, harvesting birch bark is less labor intensive.
6: Thick Spine, Full Tang
Batoning is also used to cut branches and trunks of green trees for shelter making. Chopping is quicker and more enjoyable but fatiguing and risky; the blade can bounce back or the hand slip forward. A lanyard twisted tightly on the wrist protects against loss of control when fatigued. The BK-2 is static and more controllable when batoned. Binding is less likely when circumcising with a series of "V" cuts, rather than hammering the knife all the way through. Combining a .25" thick spine with full tang provides the structural strength to prevent snapping at the hilt, after knots are encountered.
Partial and rat tail tangs can develop stress fractures at the 90 degree interval from blade to tang. This is where the knives break in half. A full tang is visible from the top and bottom, the BK-2's handles only cover the sides. Never use rocks or metal objects to baton a knife. If hammering with a knife's pommel, don't support the object with the other hand. Knife slippage may slash the support hand.
Many knife manufacturers devote minimal attention to sheath design. Randall's C sheath, was designed under the auspices of the Marine Corps. Holes were located on the belt loop and tip of the sheath, supporting attachment to vests and webbing via leather thongs or paracord. The leather keeper secured the knife in vertical, inverted and horizontal carry. Rivets provided additional security if stitching rotted. The leather was often impregnated with wax to help repel moisture.
Currently, survival knife sheaths are available in leather, Zytel, Kydex and nylon fabric with hard inserts. People consider Zytel sheaths inferior because of their low cost. It reality, they offer the best overall performance. They don't retain moisture like leather, become brittle in freezing temperatures like Kydex or rip like nylon fabric. Kydex is popular with knife collectors because of its perceived quality but Fallkniven switched to Zytel due to the failures experienced with Kydex in extreme cold. The BK-2 ships with a Zytel sheath. Once modified as discussed below, the sheath is extremely functional.
8: BK-2 Functionality
Survival training stresses a practical, risk averse approach to resolving challenges. Core strategies being advance planning, preventing injury, conserving energy and equipment redundancy. Getting separated from our pack is far from impossible; a good survival kit is effectively a miniature backpack, providing means of shelter, water and fire. The survival knife can be thought of as a back up for the survival kit, being capable of making shelter, water containers, fires, traps and digging sticks.
Bo Randall's original design objective was to produce an indestructible tool with practical dimensions, to address the extreme demands of combat survival. Strength and ease of carry are less critical to a camper or bushcrafter, that will often favor a combination of ax, utility knife, saw and spade. However, the survival knife is suited to off trail backpackers, explorers, adventurers, hunters, pilots and soldiers that require portability, practical performance and durability for abusive duty.
The BK-2 is versatile in this regard, handling everything from fuzz sticks and figure 4 traps to splitting logs. A razor sharp edge helps to make the BK-2 handle like a smaller knife during precision cuts. The Spyderco Sharpmaker takes a little practice but is the easiest way to get your knife shaving sharp. Touch up the edge in the field with repeated circular motion on an EZE-LAP. The blade should remain in contact with the rod, which maintains the consistent freehand angle critical to sharpening. Diamond rods clog with fine metal particles. Use a pink hi-polymer eraser to clean them. Wipe off any pink residue from the rod. Lubing the BK-2 blade with a thin layer of mineral oil protects against rust but doesn't taint the flavor of food.
The blade itself is excellent but there are a few niggles that need to be addressed for owners to get the most from their BK-2. It comes down to the handles and the sheath. The three bolts that secure the handles can come loose with vibration. An application of blue Loctite eliminates the issue. The Grivory handles absorb vibration well. Ethan Becker left them slick to prevent generating blisters in extended heavy use. A common complaint is that the handles feel slippery and cheap. Pictured above, fitting a section of 1 3/8" bicycle inner tube provides additional traction. Another option is to stipple the grips with a soldering iron. Micarta handles do provide additional grip and a sensation of quality. Strip the blade coating and it starts to rival a custom knife at a fraction of the cost.
The original Kydex BK-2 sheath loosened with use. A second generation Zytel model resolved that but retained the nylon web frog, which permits the BK-2 to flop about when carried on a belt. Its lack of rigidity also precludes a one hand draw. To fix, separate the carrier and sheath by unscrewing four connecting bolts. Crimp the three connecting rivets with pliers to detach the frog from the carrier. The carrier's three holes align with large Tek-Lok belt clips (pictured earlier), delivering a smooth one hand draw, comfortable vertical or horizontal (scout) belt carry and PALS compatibility. Remove the carrier and attach a Pull The Dot belt loop to support inside the waist band carry.
Some owners found the Zytel sheath initially dulled the blade; sharpening the knife a few times or expanding the blade channel with a file usually resolved the issue. KA-Bar switched from Zytel to a glass free plastic in 2011 and finally resolved the sheath dulling issue. The glass free sheath looks identical and is still referenced as the Gen 2 sheath. If you own an older BK-2 sheath that continues to dull your blade, contact KA-Bar to seek a glass free replacement. KA-Bar also sell the BK-22, which is a BK-2 knife equipped with a nylon cloth sheath incorporating a Kydex insert. The glass free plastic sheath that currently ships with the BK-2 is superior, just slap a PTD or Tek-Lok on it and you're golden.
Ethan Becker named the BK-2 the 'Campanion' but 'Survivor' would have been just as fitting. It has been in U.S. production since the mid 1980's and proven itself in extreme survival conditions. It simply refuses to break. After manufacture switched from Camillus to Ka-Bar, the 1095 Cro-Van (Sharon Steel 0170-06) received an upgraded heat treatment and even greater strength. The difference between 1095 and 1095 Cro-Van, is tensile strength via heat treatment, rather than edge retention.
Some knife enthusiasts debate the practicality of the BK-2's design. Bushcraft and camping won't require your knife to pry open
boxes or pound through green wood in freezing temperatures but survival doctrine does. The versatility and sheer
strength of the BK-2 enable it to excel in survival tasks. Ultimately, I favor the BK-2 because no rival
can compete with its 30 year, zero failure, service record.
Questions & Feedback.
Well, that's about it guys. I hope you found this guide useful. If you have any questions or feedback, feel free to contact me through the welcome page.
Ian ST John.
Copyright © 2013