You might have a collection of costume swords in your props cabinet that you’d like to convert to fight quality by replacing the blade. Sometimes this is simplicity itself, especially if you are going to pop in a very light blade such as the epee. But there are a few things to take into consideration before you start. Replacing the blade alone does not make a costume sword fight-worthy; every part of the hilt and its assembly must also be examined.
It is almost a certainty that you will need not only a new blade but also a new pommel. The old pommel is probably made of brass, so will have to be replaced. Why? Because under the strain of swordplay, the pommel will loosen quickly, so naturally the pommel will have to be squeezed down harder and more often. Brass is soft, and the threads will strip very quickly. If you really want to keep the old pommel, there is one way to keep it so long as the new blade has a very long tang. Drill the hole all the way through, so that the blade tang can stick out of the top. Then tighten an appropriate steel cap nut on top, cut off the excess tang, and you are ready to go.
If the old pommel happens to be made of steel, you’re still not off the hook. It has almost certainly been threaded 1/4 20 [English], while most fight-worthy blades are threaded 6mm [metric]. 6mm is slightly smaller than 1/4 20, so you can’t just re-tap the same hole. You would end up with less than a third of usable contact between the threads, and the pommel would strip out in no time. If you really want to keep the old pommel, drill a deeper hole and tap the entirety at 6mm (M6 × 1.0). This of course assumes that the tang of the new blade is long enough to allow for this.
Some swords have no pommels at all, or only a hollow bulge called a false pommel. This is where the center of balance comes into play. Stage combat blades are commonly about twice as thick as their historical counterparts. That extra steel places considerably more weight toward the blade and moves the center of balance much farther from the hand.
Stage combat sword work requires control at all times. If you are installing a very light blade, such as an epee blade, you may not need a counterweight. With anything heavier, however, you will probably need to add a weighted pommel to bring the center of balance back toward the hand. Does a large round pommel destroy the sleek appearance of your sabre? Sorry, but you cannot fight safely without the necessary counterbalance.
Moving down the sword, the handle and grip can cause their own difficulties. To properly seat the pommel, the handle should have a flat, solid top. Many grips on costume swords, again mainly sabres, have asymmetrical tapered shapes. If there is enough wood, you might be able to simply give the top a fresh cut. If not, you’ll need a new handle. A sloping handle end will gradually collapse under the pressure of a tightened pommel, and even the tang can begin to bend inside the handle and crack.
You might also find that the old handle isn’t wide enough to support the tang of the new blade. Even though it may look plenty big from the outside, the hollow inside may need to be drilled out in order to accommodate your new blade. This can cause its own set of problems, especially if the wood is already weak.
Wire wrapped grips, especially common on sabres but also seen on many other swords, have to be handled with great care if you plan on using them with different blades. The wire ends are anchored to the inside of the grip, so drilling through the center of the handle shears the wire ends. After that, the whole wrapping quickly unravels.
A seemingly stout guard may not be suitable for a fight-worthy blade. The slot may be too narrow for the new blade, but the guard itself may be too thin to enlarge the slot without weakening it. Even if everything fits together, tightening the pommel may cause the blade shoulder to punch through the guard. This is common with aluminum and brass guards, but it can also happen with thin steel plate. To prevent this, place a good-sized washer over the tang against the blade shoulder. The washer spreads the pressure and protects the guard. Properly placed, it also helps keep the blade’s vibration from being absorbed by the dampening materials of the handle, allowing the blade to ring longer.
Finally, all of the parts may be suitable, yet incorrect assembly can still leave the sword unfit for stage combat. Two errors are particularly easy to make.
First, the blade must be mounted in the correct alignment. The cutting edge should be in line with the actor’s knuckles and therefore with the knucklebow. If the blade is mounted 90 degrees off, the actor will be striking with the flat rather than the edge—like trying to drive a nail with the side of a hammer.
Second, an asymmetrical guard must also be mounted correctly. It may seem logical to align its longest section with the knucklebow. That looks attractive and allows the sword to rest closer to the hip, but it provides protection where the knucklebow already provides it. The longest section of the guard historically would instead run crosswise to the knucklebow, protecting the front and back of the hand.
Correct parts do not necessarily make a correct sword. Their alignment and assembly matter just as much.