The Cold Steel ‘Kobun’ is a lightweight, concealable combat knife with a nearly-indestructible blade and an almost-unbelievable price point. I won’t make you wait for the big reveal here: it’s not a very good general-purpose knife (because it’s a tanto), but for what it is, it’s freaking awesome. If you want a midsized fixed-blade tanto, Cold Steel really nails it here.
The designers at Cold Steel are particularly fond of tanto blades. A quick peek around their online store shows at least fifteen different fixed-blade tantos in their catalog, not including plastic training knives. This makes sense, because it was Cold Steel that helped popularize the tanto design here in the 1980s.
The tanto blade, Japanese in origin, evolved as a secondary stabbing weapon able to penetrate laminated armor. I don’t have any laminated armor lying around, so I tested this by stabbing through an old shoe whose multiple layers of leather, textile and rubber are surprisingly tough. The Kobun nailed this shoe to the deck with minimal effort, with about a half-inch of tip stabbing into the planking.
This modern ‘American’ form of the tanto features a thick spine and typically a deep hollow grind, a heavily reinforced tip, and a sharply angled secondary tip where the blade bevel meets the tip bevel.
We don’t need to stab through laminated armor very often these days, but the tanto design still excels as a combat knife: the plain handle is comfortable with all forward and reverse knife grips, and the reinforced tip is almost impossible to snap off. This is why it remains popular among combat-knife makers like Emerson Knives and Ka-Bar.
The Cold Steel Kobun has a 5.5″ blade made from hollow-ground Japanese AUS-8A stainless with a hardness of RHC 57-59. The spine of the blade is .125″ thick, and this thickness extends forward almost all the way to the tip. Beneath the molded Kraton grip, the tang narrows slightly toward the pommel. It’s not quite a ‘full tang’ but it’s far too thick to be called a rat-tail.
The whole knife is 9 7/8″ long, but at only 4.3 ounces it’s lighter than many 3-inch tactical folders. The molded polymer sheath (included) adds only 2.5 ounces, making the entire kit extremely lightweight. It’s also very slim: even the hilt is only 5/8″ wide, and the sheath is barely an inch thick at its thickest point which is the belt/boot clip.
The sheath deserves extra mention. It’s designed for right-side carry, inside your boot or inside your belt; if you want to carry on your left side you’ll have to improvise. It holds the knife very firmly by gripping the rubbery hilt, and the belt/boot clip is detachable if you prefer to secure the sheath to your gear with paracord or 100-mph tape.
Many knife makers (cough SOG cough) give you a reinforced Nylon belt sheath, but make you pay extra for a good rigid one like this. Cheers to Cold Steel for giving you the right sheath up-front.
I didn’t have many opportunities to wear this knife for extended periods, since my jurisdiction doesn’t allow fixed-blade EDC. I did get to wear it all day during a few shooting and hiking outings in a neighboring state with more reasonable knife laws. Here’s what I noticed:
- It’s so light I never noticed the weight at all.
- The sheath never shifted around or fell out, and neither did the knife: both were extremely secure.
- I’m a pretty fit guy (no muffin-top here) but when I wore it inside my belt at four o’clock the long handle still jabbed me in the kidney.
- Boot carry with any of my footwear was impossible, because I don’t own any cowboy or engineer boots.
- Drawing this knife from high on your hip is fairly simple (although a bit awkward) but you’ll have to be very careful re-sheathing it.
Newsprint: Slicing hanging newsprint is a good test of a blade’s sharpness. The Kobun had a very good factory edge, and it sliced hanging newsprint right out of the box. It sliced even better after a quick strop, but the fairly obtuse edge angle (no sharper than 40 degrees) never got quite as sharp as our benchmark Mora knives. It’s no disgrace that the Kobun couldn’t slice hanging Shotgun News crepe paper; this requires extreme sharpness, which a stabbing blade isn’t primarily engineered for.
The Kobun did a bang-up job as a field chisel, however, when I needed to bevel the corners of a 2×4 to stick it into my steel silhouette target.
I have little doubt that the Kobun would have conquered the Shotgun Newsprint if I had reprofiled the edge to 30 degrees, but I decided not to do this. Tantos are meant to be rugged (and AUS-8A isn’t a supersteel) so I left the grind at 40 degrees and didn’t look back because the Kobun already earns an A– as it is.
Rope Cutting: This tests the knife’s ability to power through tough, resistant materials. The Kobun’s sharp blade and solid grip allowed it to pull through a loop of 3/4″ Manila in a single determined stroke, and the cut was almost laserlike in its precision.
When I laid the rope on a cutting board, the results weren’t as good. I blame the blade geometry. Tantos have almost no belly and this one has no serrations, so sawing flat down into the rope is not a very efficient cutting technique here.
This kind of blade can only be pushed downward through the rope like a guillotine blade, and the Kobun was sharp enough that this would have been fairly easy if the handle were offset like a Santoku or a chef’s knife. As it was, however, the tanto’s straight-line handle crushed my knuckles into the cutting board, and I ended up doing most of the cutting with the angled secondary tip. Grade: B.
Box cardboard tests the knife’s ability to hold its edge while cutting through a tough, abrasive medium, and the Kobun excelled at it. Hollow grinds are usually somewhat tedious to pull through cardboard, but the Kobun’s long, sharp blade and grippy handle made it easy. The cuts were clean and controllable; the edge didn’t wander through the cardboard until my hands started to get tired after the 100-foot mark.
After slicing about 100 feet of corrugated box cardboard across the grain, the edge had picked up some slight abrasions that you could just feel with a fingernail. It didn’t slice newsprint cleanly at this point, and I had to put a lot more muscle into the cutting. My left hand was getting pretty tired of holding the cardboard, but my right hand was still going strong until the blade finally began catching and plowing through the cardboard at almost 130 feet.
130 feet is astoundingly good for an ‘upper-midgrade’ steel like AUS-8A. Grade: A+.
Ease Of Sharpening
The Kobun’s AUS-8A held its edge like a supersteel, but still lived up to its reputation for easy sharpening. It was newsprint-slicing sharp again after about ninety seconds of gentle edge-polishing on the Sharpmaker and a few strokes on the strop. Grade: A.
The Kobun has an extremely slender grip, but it does have a slight palm swell and the excellent texture of the Kraton keeps it very secure in your hand whether wet or dry. It’s so thin it looks like it has to be uncomfortable, but I really had no problems with it at all.
It was only when I compared it to the handles of other mid-sized sheath knives that I noted the difference. The SOG Seal Pup‘s sculpted finger grooves, the Mora Bushcraft’s perfectly-molded rubber, and the hand-filling mass of the Robson X-46 all provided better blade control and leverage with less effort.
If the Kobun’s slender grip were made of anything but Kraton, it would probably be terrible. The Kraton gives it pretty good handling, but not as good as a general-purpose hunting-survival knife.
Here’s one final safety note you should pay attention to: the Kobun has no jimping on the spine and no choil or ricasso on the front of the blade, so there’s no reason to choke up on the handle. The rubbery hilt is there to remind you to keep your fingers and thumbs firmly seated and buckled until the ride has come to a complete and final stop, and this picture shows why.
The grip has no curve or molding or finger grooves to tell your hand if the blade is facing forwards or backwards, and if you grab it the wrong way and reach for the non-existent jimping you’ll end up doing this. It’s sharp enough that you’ll have to be lucky to avoid getting cut.
Grade: B-. As long as you keep your fingers behind the hilt.
- Steel performance (sharpness, edge retention, ease of sharpening).
- Value for money.
Least Favorite Features
- The tanto blade design has almost no belly, and is mediocre for many real-world knife tasks.
The Cold Steel Kobun has a lot of great things going for it: light weight, comfort, easy concealment, a good sheath, great sharpness and amazing edge retention. It has one other feature I alluded to earlier: an incredible street price of only $30.
It may not be an ideal general-purpose knife because it’s a tanto, but as a tanto it’s an amazing value for the money. It might be to combat knives what the Mora is to bushcraft knives: sharp and sturdy and mind-bogglingly inexpensive. You could even round off the secondary tip and make yourself a custom spear-point, if the tanto point was a deal-killer.
Type: fixed-blade boot/combat knife. Modified full tang construction.
Blade style: hollow ground tanto.
Blade: 5.5″ long by 1/8″ thick.
Steel: Japanese AUS-8A stainless, 57-59 RHC.
Overall length: 9 7/8″
Weight: 4.3 ounces (6.5 ounces with sheath)
Sheath: Molded polymer w/right hand inside belt/boot clip.
Price: $60 MSRP, street price $30.
Manufacturer’s link here.
Ratings (out of five stars)
Simple but attractive.
Good sharpness and outstanding edge retention with easy sharpening. It’s the blade design, not the steel or execution, that hold it back.
A handle this thin should be really uncomfortable, but it’s not.
Don’t worry about this knife.
Overall Rating ****
An amazing value for a $30 knife.