BARR KNIVES

ESSAYS ON A CUSTOM KNIFE 06/98

• Cutting Ability
• Steels Used
• Design

The easiest way for me to describe the process of making a custom knife and its attendant technologies will be to start and finish one solely for this academic project. After five seconds of careful deliberation, I decided to call it my school knife. I like the sound of that. A folding knife will be more of a challenge for me and would force me to learn more in the process, but since the object of the project is to document what I already know, I'll make it a fine quality fixed blade knife. I have made quite a few fixed blade knives but I have always made compromises in the name of expedience in my previous work. This time I don't intend to force myself into any pre-conceived notions of productivity for the purpose of working to a price point as I have with my past knives. The first task is to select the steel for the knife.

The selection of any component of a knife is dependent upon the intended use and form of the final product. The same blade material that is perfect for a small knife may not be advisable for a large Bowie or sword. But the proper selection of blade steel, even though the differences only show up in hard use, is the most critical aspect of designing a knife. The choice and heat treating of the blade steel are fairly invisible when the knife is completed, and only come into the light when the blade is being used. Hand made knives often cut better for longer than their factory made counterparts, but I don't delude myself that the average six hundred dollar folding knife will cut as well as thirty twenty-dollar knives made from the same steel.

As an illustration, a few years ago I bought a small camp-axe at Yard Birds when they were going out of business for something like two dollars. I took it home and sharpened the bujeezus out of it so it was razor sharp and used it to do some pruning the next day. After chopping through two numerous small branches and at least two of about 4 inches in diameter, that stupid little two-dollar axe would still shave the hair on my arm.

CUTTING ABILITY

I look at cutting ability as only one aspect of the finished product, and it isn't anything that I would base my whole marketing plan on, although some knifemakers do this with some success. Some are even able to trade on their cutting ability even though their knives don't cut well.

The two things that determine the cutting ability of a knife are its edge geometry and the heat treatment of the steel. Although dependent on the intended use of the knife, within those parameters, edge geometry and proper heat treatment are paramount. Different purposes require different combinations of attributes. Generally speaking, blade hardness translates to good edge retention and softness to easier sharpening.

The blades on a wood planer are generally made from abrasion resistant steel like D2 and use a fairly wide included angle at the cutting edge. The knife in the sheath on the meat-cutters apron uses a very thin edge that is sharpened often on a whetstone in a pocket of that same apron or nearby. The meat-cutters knife is in use constantly and no matter what it is made from, it gets dull. If I make a knife out of an abrasion-resistant steel like D2 for your meat-cutter, I will soon have an unhappy customer, since a D2 knife is murder to sharpen on a stone.

There are also artistic intangibles that can make a knife anything from very personal property to fine art. The intended use of this knife will be to carve out a few credits from the faculty at The Evergreen State College (figuratively speaking, of course).

The heart and soul of the knife is in the blade, and my choice for blade material must be something that reflects its intended use. All of the steels I have available have enough carbon that they can be hardened. Anything sharp can be called a knife, but if I am to sell it as a knife, then the blade edge should be as hard or harder than hardened steel, and sharp, too. The business of hardness is a slippery slope, because sometimes with hardness comes brittleness, which is a lousy attribute in a sword, but is of less consequence in a planer blade which is relatively thick, ground at a large angle, and is not subjected to significant twisting forces. The Project knife will be in the form of a large Camp Knife or Bowie. This knife should be comfortable and balanced enough to chop kindling with, but not overly heavy as are many similar production offerings.

Any piece of metal can be sharpened and called a knife, but to make something better/more appealing than the mass-produced knives in the cutlery stores, it needs to look better and perform at least as well as or better than its commonly available counterpart.

STEELS USED

I have made knives out of O-1 toolsteel, 1084 spring steel, and ATS-34 stainless steel. Most of my knives have been made of O-1, followed by 1084, and just a few, some still in process- from ATS-34. For this project I chose 1084 spring steel for a number of reasons. I have some of suitable size, can heat-treat it myself with confidence, and I can turn out a blade with visible evidence of the hardening process. This relieves the faculty of feeling obligated to skin animals, chop any wood or perform any free-hanging-rope cutting tests for a usability assessment of my work.

I have an assortment of the steels in my shop. Precision ground steel is convenient to use since it is supplied in exact dimensions so that after cutting out a knife design; the two large sides of the blade are flat and parallel. This saves time because precision joinery requires well, precision, and if you don't have it to begin with, you have to make it yourself. I also have some ATS-34 stainless steel. It was furnished cold rolled to dimensions, and that means just what it sounds like. It was extruded from a larger piece of steel by an ungodly powerful machine that can squish steel without even heating it. I also have some hot-rolled 1084 spring steel. It is furnished as it comes out of the rolling mill and has a rough surface and approximate dimensions. Although more labor intensive because of the necessity of finishing all of the sides, 1084 has advantages in its aesthetic possibilities.

I spent some time working on some nice mokume-gane for the project knife furnishings before even deciding on the blade shape. When I laid out all of the pieces ahead of me, it was difficult to decide which one to finish. At first I wanted to do them all, but I was most drawn to one blade. The knife blank I had cut out but hadn't felt inspired with before was calling to me.

While the furnace was hot and cooking some mokume, I threw that blank in there with the mokume at 1700 degrees. I hammered along the edge of the blade just a bit, not enough to form much in the way of blade bevels, but enough to give the whole blade a bit of curve, and so give it at least the possibility of style outside the box of its rectangular beginnings. Because of injuries, my hammering ability is not very robust in the face of all the hammering required to become a decent blacksmith. I must be content with knowing where I need to hit and try to do as little damage as possible. I did very little damage this time, and have commenced to grind upon the result.

One thing that cannot be understated about forging is that it's hard, really hard work even when the iron is hot. Swinging the hammer by the forge works up a sweat that can cause your glasses to slide down your nose at speeds in excess of forty miles per hour. In 1992 I took a weekend class in bladesmithing taught at the shop/home of Don Ferdinand. I learned about gas forge design, and used what I learned to build my first propane forge, a bit about knife design and grinding and how to swing the hammer. I forged and brought home four knives from that weekend and still have them all, because I never finished any of them. They each look like the beginnings of a knife, but I have not yet seen the knives within the clumsily wrought shapes, and I'm still disinclined to put effort into them. I just think they are all just plain butt-ugly anyway, so they are stored with all of the other butt-ugly knives that I have made over the years, in my drawer o' humility.

DESIGN

One characteristic I noticed on the ancient weaponry that I saw on my trip to Italy was the distal taper. Knives, swords, guns and their combinations were not carved out of huge rectangular hunks of raw material, but were forged out by the power of the hand held hammer from blobs of red hot semi-plastic steel. The path of least resistance in making something long like a sword or knife will be to draw out only as much material as is needed for the structure. This leaves the thickest part usually at the hilt, right where the handle meets the blade.

If you wanted to gain reach with your weapon, it needed to be longer. Longer is good but comes at the cost of more weight for a blade of similar strength. And greater weight can be a definite disadvantage in any combat situation short of facing a fully armored opponent.

The way to get the best strength to weight ratio in a longer blade is through the triangulation of its structure. That means a distal taper along its longitudinal axis. This describes a blade that is thickest right where the handle meets the blade and gets thinner toward the point. If the blade is of full-tang design, the tang should taper towards the butt of the handle as well.

My tendency is to leave blades a little thick at the point. I like the point of the blade to be strong enough to pull staples or stab through a suit of armor or whatever. I have seen a lot of custom knives with broken tips and I don't want any of my work to end up looking like that. A few times a year, someone will ask me to fix such a knife and unless I am in great financial need, I will decline.

When a blade breaks, it is not usually due to abuse by the user. People who abuse their knives usually don't buy custom knives. They are usually satisfied with factory-made offerings, which are generally engineered to the lowest common denominator. It's kind of scary when you think about it.

I want to be able to drop the knife, point first, onto a concrete floor without significant damage to the point. I don't often do this test on knives with handles, because it's tough on the handles. I also like a blade edge to be really hard so that it will retain its edge as long as possible. So I leave a little extra meat behind the point. Additionally, in combat it is just as important that a knife is suitable for both slashing and thrusting and that the knife not demand absolutely perfect technique from the user.

The critical elements of the Project Knife design are the blade profile, now forged to shape, the distal taper, pinned construction, flat grind, hand-sanded finish, and the differential temper.

The distal taper and all the flat grinds were accomplished on the two grinders with a careful eye and a fairly steady hand. I use so many techniques for holding the steel against the abrasive that it would take ten photographs to show all the strange positions I get myself into next to those machines. I know I came up with a few new ones while working on this knife.

The pinned construction is invisible, and provides an appropriate balance to the fit of the parts. It looks just great and will provide a good surface for engraving. The hand sanding was applied with a good amount of sweat. Unfortunately I haven't a blow-by-blow description of all the steps taken in making this knife. It just doesn't happen that way. I try new things so frequently that it's hard to know just which technique is the most viable.