The Sword of Ehud
by Ken Cox
Three thousand years ago a man named Ehud set his mind to kill Eglon, King of Mo’ab. For 18 years Eglon had unjustly ruled Ehud’s people, forcing them to build a Mo’abite fortress within the accursed City of Palms. Now Ehud, a Judge from the tribe of Benjamin would single-handedly deliver his people from this false King.
To fulfill his plan Ehud made a double-edged sword the length of his forearm from elbow to bow finger. He strapped the sword to the inside of his right thigh and carried it past the bodyguards, deep into the King’s fortress. Kneeling before King Eglon, Ehud said, “I have a secret word for you.”
“Keep silence,” warned Eglon, dismissing his guards. Alone now with the King, Ehud drew closer, face to face, and said, “I have a message from God.” The King’s eyes widened. He leaned forward to rise from his throne and Ehud’s left hand reached for the hidden sword. Eglon never saw the blade that plunged deep into his belly and pinned him to the throne.
Ehud bolted the doors to the chamber, let himself down from a covered balcony, and escaped to the hills. Blowing the Ram’s Horn, he gathered the fighting men of Benjamin and returned to take the Mo’abite fortress by storm. And so by one man’s act of daring, God delivered an entire people from slavery.
I discovered this story after reading how Jesus said that anyone who does not have a sword should sell his cloak, if necessary, and buy one. As a family man on a budget I wondered how small a blade I could buy and still have it qualify as a sword. The bible describes two swords, one belonging to Joab and the other to Ehud, as small enough to conceal beneath clothing. A careful reading of the story of Ehud revealed a sword measuring 13.5″ in total length. With a little more study I had enough information to make an educated guess at the other dimensions of Ehud’s sword. Now I needed to find someone who could take the sword in my mind, and turn it into a real sword in my hand.
I searched the knife publications and the Internet for a suitable knife maker and eventually found Gene Osborn of Center Cross Metal Works. When I saw Gene’s logo, three crosses, and read his philosophy of knife making I thought we would have a good match of interests. The fact that he had graduated from the Navy’s School of Heat Treatment and Metallurgy made everything a plus.
I called Gene on the phone and we talked about knives in general. When we got around to the Sword of Ehud, I could sense Gene’s interest growing and he began to share his personal history with me.
Gene joined the Navy 20 some years ago in order to learn everything he could about metal. Recognizing his commitment and motivation, the Navy gave him extensive schooling in metals and trained him as a Nuclear Components Welder. While attending heat treatment and metallurgy school, Gene made his first knife, a 440C stainless steel dive knife for a SEAL instructor.
The Navy put Gene to work on nuclear submarines where he met his wife Pat, a Nuclear Health Physicist. Pat now runs the Center Cross Metal Works website, takes care of Gene and their kids, and sometimes helps other aspiring web-masters get a start.
Since the Navy, Gene has worked as foreman in steel fabrication plants, CNC machinist, welding engineer in a steel foundry and custom knife maker. You can tell he has a strong interest in steel. “I love what I do,” says Gene.
Gene quickly warmed to the idea of making Ehud’s sword. We agreed that it should, by design, function as though Ehud’s life and the freedom of his people depended upon it. For that reason it should have the balance and proportions to genuinely slash through a determined defense (tenderize, as Gene put it), penetrate body armor and deliver a fatal wound with a single thrust. If made right, this sword would give new meaning to the phrase “pocket battleship”.
Since we had an historically prescribed length limitation of 13.5″, Gene and I knew it would take some new thinking about grip shape, overall proportion, blade contour and grind to elevate this knife into the domain of swords. Generally speaking, a blade less than 9″ in length does not slash effectively, and this limitation applies even more so to tapered dagger blades such as Ehud’s.
In order to distribute the blade mass more favorably for slashing, Gene proposed a technically difficult flat grind. This would leave more metal in the blade than the hollow grind usually associated with daggers. Gene also suggested a mirror polish on the blade to further reduce friction and drag. I, on the other hand, concentrated on designing a symmetrical grip that would enhance the slashing power of the blade without detracting from its thrust.
As part of my research I reviewed my large collection of knife magazines and edged-weapons publications. Using the Internet, I discussed design parameters with knife makers and martial artists around the world. The martial arts community gave me the phrase “snap cut”, describing a whipping, drumstick, baseball-throwing movement. They confirmed the concept of a heavy, balanced dagger as a slashing “tenderizer” in preparation for the final, intended thrust. Additional influences came from Bill Bagwell’s “coffin shape” grip, Charlie Porter’s “hammer pinch” grip, and James Mattis’s grip designs in general. Gradually, a design emerged that would enable the middle and ring fingers to accelerate the blade around the “pinch” between thumb and index finger, and yet keep the hand from sliding forward in a thrust.
Given the religious nature of this sword, I began my drawings with prayer. At each step along the way I tested the design by imagining myself in Ehud’s place. I also imagined what kind of knife I would want if I absolutely had to fight a grizzly bear. I constantly weighed the design against these standards. After two solid weeks of drawing, making cardboard models and obsessing in general, I sent the final set of overhead plan, side elevation and cross-sectional drawings to Gene.
When Gene received the drawings we had another long talk on the phone. I think during that phone call, for the first time Gene and I began to believe we could actually make a 13.5″ sword. He had very kind things to say about my grip design and my drawings. We also decided the design warranted the expense of BG-42 steel.
Finalizing the design of the grip we chose ebony (which grows in the biblical world) as an historically possible scale material. We put a layer of sheet brass under the ebony as an accent and a spacer of black micarta against the steel. To hold the seven layers of knife together we used seven brass pins. This theme of seven appears again in the sheath.
Gene suggested shrinking the scales and spacers in order to make the steel stand out a little. Adding file work to the projecting edges of the grip would further help keep the hand from sliding forward in an all-out, desperation thrust. A bull-rider would love to have a grip as positive as the one provided by this combination of shape and file work.
Timken-Latrobe, the exclusive manufacturer of BG-42 sent us many pages of technical data, and specific information on heat treatment. Michael Petro, metallurgical engineer for Timken-Latrobe gave me more than an hour of his phone time explaining the Vacuum Induction Melting and Vacuum Arc Remelting process they use to make BG-42. He also told me some of the history of this steel and explained the concept of micro-cleanliness. Now, when I think of BG-42, I think clean. I came away very pleased with our choice.
Within days of receiving the steel, Gene sent me photos of the shaped and finished blade prior to heat treatment. Gene had stayed within twenty thousandths of an inch of my drawings and managed to make the sword balance at the choil between the Center Cross logo and the grip. He also surprised me with photos of a remarkable sheath and harness.
The sheath, which Gene designed, includes a waist belt adjustable from 28 to 46 inches, a hip suspension strap and two additional straps to hold the sword against the thigh. The sheath has seven layers of cowhide, sheet brass and buckskin protection. Please read the word “protection” as intended for the wearer, not the sword. The whole sheath and harness adjust and work so well that any size wearer can perform gymnastics and generally get pretty “rough and tumble” without fear of losing the sword or receiving injury from it.
Given Gene’s years of heat treating a variety of steels for so many different applications, I very much wanted him to do the heat treatment in-house. Not many people heat-treat BG-42 because of the extremely high temperatures required and the need to isolate the steel from the atmosphere during heat treatment. Chris Reeve does his own knives. Canadian knife maker Thomas Haslinger and Paul Bos, renowned heat treatment specialist for Buck Knives, will take in other knife maker’s work as a professional service. Gene agreed to do the heat treatment only after the first blade we sent to Thomas Haslinger suffered severe damage during shipment. With input from Thomas Haslinger, Tom Mayo and Timken-LaTrobe, Gene developed a process he trusted and further improvised a way to use his present argon atmosphere furnace for the job.
I won’t go into all the details because I probably couldn’t do Gene’s process justice in the space available. This all comes under the heading “don’t try this at home” anyway. Suffice it to say the process involves multiple heating and cooling cycles, a soak in methanol and dry ice at 107 degrees below zero, and it produces a very tough steel at 62.5 on the Rockwell Hardness Scale (Rc).
As you may know, many knives characterized as “hard” come in at 59-61 Rc. If we had used the heat treatment process recommended by Timken-LaTrobe for BG-42, this blade could have measured as high as 64 Rc. Gene aimed for a more conservative hardness in order to maximize toughness and strength. Independent testing puts this blade at 62.5 Rc, right in the middle between its full potential and the maximum for more conventional steels.
The sword you see in the picture measures 13.425″ in overall length, and a reassuringly hefty .25″ in thickness. The ratio of the blade length, 8.3″, to the grip, 5.125″, incorporates a proportion (1.618 to 1) called the Golden Section. Architects and artisans have used this ratio to design beautiful buildings and art objects since the time of the Great Pyramid. In this case, with some help from Gene, the sword balances perfectly at the “golden section” meeting of the blade and the grip.
Every design feature contributes to the sword’s function, from the drag-reducing mirror polish to the multi-faceted and tapered grip. In my opinion, the shape of the grip increases the power of this sword enough to set it apart from the general family of daggers. It may not chop like a Bowie or a hatchet, but it will easily deliver an incapacitating slash.
The flat grind gives the point a strong, unbreakable cross-section all the way to the tip and, if you look carefully at the photograph, you will also notice the absence of a bevel at the edge. Closer examination by eye and touch reveals a rolled, or convex edge. The combination of a flat grind and convex edge provides maximum strength and edge retention with minimum drag. In an informal test of sharpness, the blade cut printer paper smoothly and effortlessly with the entire length of both edges, from root to tip.
I found designing and making this sword a very rewarding process. As an object of contemplation, the sword has given me a better understanding of my own faith and human condition. It has led me to understand that non-violent solutions to conflict have deeper significance when one has a weapon and therefore a genuine choice.
Ehud’s sword probably marks a once in a lifetime project for me. I don’t have the funds to do this as a regular hobby. I thank my wife and children for their support and Gene Osborn for faithfully making my dream come true. If you have a dream blade in your head, give Gene a call and let him put that knife in your hand.
Center Cross Metal Works