A common topic of debate among sword aficionados on the internet is which swords are peened, and how this is done. Some of these discussions can be somewhat misleading about what is historical and what a peened sword is. We thought we would try to illuminate with some fact-based historical examples and discuss a bit of what this is in actual structure and form. Mechanically speaking, peening is a process of plastic deformation, much like riveting, in which a piece of metal is struck with a rounded peening hammer, causing it to change shape by expanding from the point of impact.
On a sword or dagger the part that is peened is the end of the tang (the part of the blade that is inside the guard, grip, and pommel) where it projects through the pommel. Hammering the end of the tang causes it to spread out and widen over the hole through which it projects, thereby preventing the pommel from being able to slide back over the peen. This process will mechanically tighten the hilt of the sword locking the pommel down and holding the guard, grip, and pommel as a unit.
On historical swords the tang was often a different material than the sword blade itself. Period smiths would use iron for this portion of the blade for durability and ease of construction, while the rest of the blade was usually steel. The small end of the tang that sticks out the top of the pommel is the part that is peened over. This can be done when it is red hot or room temp. If it is iron there is no real difference between the two. If the tang is steel then it is best to do the majority of deformation hot. In the following sequence of photos you can observe a pommel with a rod (representing a tang) protruding through, the tang is then heated, and hammered to deform it. At this point the end of the tang is larger than the hole through which it initially passed.
Sometimes, as above, the tang is peened directly above the pommel. At other times, there is a nut or washer atop the pommel between the peen and the pommel. This is called a peening block, or nut, and is a common feature on medieval and Renaissance swords. In the images below the first sword is peened directly over the pommel, while the second sword employs a peening block between the peen and the pommel. Both methods are historical.
Part of the difference between the two is simply aesthetic. A peening block allows a bit of extra decoration, but it is also functional. Swords that are used require periodic maintenance, such as regripping or hilt adjustments, and occasionally might need substantial repair after hard use. A peen block allows a smith or cutler to more easily disassemble a sword by filing off the peen without marring the pommel. Disassembly of a sword with a flush peen often requires damaging the pommel, and then drawing out the tang to make it long enough to put back through the pommel and re-peen it. In effect, use of a peening block makes it easier to maintain and repair a sword throughout its working life.
In historical swords the amount of material that is peened varies quite a bit from a small flattened area to a larger form that protrudes from the pommel. Modern sword lovers are often surprised at the small diameter of many medieval and Renaissance tangs, and therefore peens. Below are photos of artifacts from the Oakeshott Institute collection, showing a variety of peens on original swords spanning the 11th - 17th centuries.
The peen on this pommel also shows a dramatic taper inside of the pommel. Where the tang enters the pommel is is over .5 inches wide, but on the near side where it is peened it is less than .25 inches in diameter.
This transitional rapier features a square tang where it enters the pommel, which then tapers and becomes round by the time it emerges from the peening block. It is significantly less than .25 inches in diameter.
15th C single handed sword with bead pommel nut
16th C Rapier pommel peen on stub at top of pommel not a separate nut
15th C longsword pommel peen
As you can observe, the dimensions of the tang coming through the pommel vary a great deal historically. While some were up to a quarter inch in cross section, the vast majority of historical tangs and peens were much smaller, usually 1/8th of an inch or less. A properly constructed sword does not need a massive tang to make it secure and functional. Instead, the mass of the tang needs to be thick where it will encounter the most stress, and thin where it does not.
Peened hanger early 17th Century - you can check out more detailed models of original swords here.
The perceived thinness of some tangs is often used by well-meaning folks to challenge the quality of some pieces that are, in fact, quite historical. This is not to defend poor quality reproductions that are rarely strong where they need to be, but to point out that a small tang diameter at the peen is very different from the justly maligned "rat-tail" tang sometimes used in cheap modern swords. Medieval smiths were quite economical with their use of materials and the tang area of a sword was constructed with sufficient size and material to make a solid sword. This can mean a tang that is quite thin and narrow in some swords. Others will have a wide tang but when viewed from the side it can be very thin. Both medieval smiths and quality modern makers recognize that overbuilding parts of swords can be almost as destructive of their functionality as underbuilding.
The peen holding a sword together is an important aspect of its construction. Like the sign hanging in our shop says "Don't peen it 'till you mean it!".
Nathan Clough, Ph.D. is Vice President of Arms and Armor and a member of the governing board of The Oakeshott Institute. He is a historical martial artist and a former university professor of cultural geography. He has given presentations on historical arms at events including Longpoint and Combatcon, and presented scholarly papers at, among others, The International Congress on Medieval Studies.
Craig Johnson is the Production Manager of Arms and Armor and Secretary of The Oakeshott Institute. He has taught and published on the history of arms, armor and western martial arts for over 30 years. He has lectured at several schools and Universities, WMAW, HEMAC, 4W, and ICMS at Kalamazoo. His experiences include iron smelting, jousting, theatrical combat instruction and choreography, historical research, European martial arts and crafting weapons and armor since 1985.