Blade thicknesses and distal taper

Blade thicknesses and distal taper of European swords from the period 10th-15th.

Having been making medieval swords for almost 15 years (and actually always being interested in them), I encountered many aspects that were not completely clear and required more extensive research based on historical sources and true measurements of the original swords. This concerned, for example, historical balance ranges, weight, distal taper and thickness of the bhlade in general, and others. Most often, these cases concerned dimensions that are difficult to find in books and which became the basis for speculation and erroneous interpretations.
Today I would like to focus on the blade thicknesses of European swords from this period.

Measurement area
When we mean 'sword blade thickness', we most often mean the measurement point just below the crossguard, which is ultimately the maximum thickness zone of the blade. This is a place that is visible and can be measured. However, in many cases on historical swords, it is even thicker, e.g. in the area under the crossguard or just behind it, under the grip. This is an important dimension that affects the distribution of mass and stresses of the entire sword. Personally, I used to measure the thickest part of the blade, which is within +/- 10mm of the crossguard, ...
Of course, this is only one point of measurement, which does not really say much about the mass distribution of the entire sword and would require measurements in many places along the entire length as well as taking into account the type of cross-section of the blade (more on this later).

The most common issues and dilemmas
In the context of modern reconstructions of medieval swords and mass production, the following questions arise:
- what were the historical thicknesses of blades in these places?
- were there any standards, ranges that are appropriate and correct for each type?
- can the blade be 'too thin' or 'too thick'?

I will try to answer them, of course based on the analysis of the original swords, because they give us a real view on these matters.

First of all, there is no clear, simple answer here, unfortunately.
The thicknesses of blades varied greatly, depending on:
- blade type
- production period
- technological possibilities
- the working style of a given maker in the Middle Ages
- purpose of the blade

In short
If you really try to give a short and simple answer: it ranges from 2.5 mm to even 12 mm at the thickest area close to the crossguard. 
However, to be precise, you need to determine the blade thickness ranges for individual cross-sections and the type of sword.
Based on the measurements of original swords, well-preserved finds in which the measurement is reliable, measuring the thickness of the blades just below the crossguard, it can be assumed that:

1.
One-handed swords with fuller, from the period 950-1100 have a blade thickness range from 2.5 mm to 7 mm, with the most common range being 4-6 mm.

2.
One-handed swords with a ridge from the period 1300-1400 have a blade thickness range from 5mm to 10mm, with the most common range being 5-8mm.

3.
Longswords with fuller, from the period 1250-1400 have a blade thickness range from 3.5mm to 11mm, with the most common range being 5-7mm.

4.
Longswords with a ridge (or with a flat area) from the period 1250-1400 have a blade thickness range from 4.5mm to 11mm, with the most common range being 6-10mm.

The data was obtained from measurements of 380 original swords, only from the period 900-1450, from various regions of Europe, based on own measurements, data obtained directly from museums and scientists, publications, catalogs and private sources.

So, to answer the question whether a blade can be too thin or too thick, the answer is Yes, as can be seen from the ranges of the original, historical blades. However, as in the case of balance or distal taper, this parameter is only a component in the context of other dimensions and cannot be treated as an indicator of the quality of the sword, independently of other parameters.

Distal taper, in the context of relation to maximum thicknesses

Distal taper is a gradual reduction in blade thickness, which is a very important factor affecting weight distribution, deflection and balance.
However, this is sometimes misunderstood as absolute reduction in thickness as a feature of a well-designed blade. Meanwhile, depending on the type of cross-sections, type and length of the blade, the cross-sectional area in a given place is more important than the distal taper. It is this factor and its gradual reduction to the tip that is crucial for the dynamic properties of the entire sword.
What does this parameter relationship provide and how does it affect the entire sword?
Thanks to this, the blade has different stiffness and allows for deflections that absorb vibrations and pressure, which prevents the blade from breaking or deforming. Thanks to this, the blade is flexible enough to fulfill its functions, depending on the type and purpose. The cross-section of the four-sided, diamond tip of a Type XV blade looks different from that of the flat, lenticular tip of a Type X blade. 
By measuring only the thickness of the blade, without taking into account the width and cross-section, we sometimes find Type XV blades still have very thick tips (4-5 mm in the middle part of the cross-section).
Apparently, the distal taper is small, but due to the fact that the blade is very narrow and stiff in this place, the dynamics and stiffness of the sword are very good. Therefore, the distal taper, measured without taking into account other parameters, does not give us an idea of the properties of the entire sword.
The problem here is also that it is difficult to give representative examples because the parameter ranges are very wide. It's like trying to give the 'correct' historical weight of Petersen type H swords, because there are examples ranging from 900 to 2000g.
The tips of the Type XV blade, narrow and more pointed but thicker, with a ridge, are adapted for penetrating and punching holes in armor. This is, of course, in response to plate armor, which would be much more difficult to penetrate with the wide tip of the Type X blade.
Still, you should be aware that all these values were not subject to any standardization and were produced in very different ranges, by different makers, in different styles and qualities, which we now examine in general as original medieval swords. 
Deciding whether a sword is 'better' or 'worse' remains then quite a subjective judgment today, in relation to original swords and is not the right approach if the modern reconstruction reflects the historical ranges of parts within a given type.
An interesting consideration is the analysis of changes in the thickness of the blades of fuller long swords (Oakeshott Types XIIa, XIIIa, XVIa) dating mainly to the 14th century. It turns out that the distal taper usually measures 5 to 2 mm and 7 to 2.5 mm (the first measurement at the crossguard, the second measurement 100 mm from the tip, good condition of the blade). With a blade often 55-62mm wide and a hexagonal cross-section with a narrow fuller, this gives a really large cross-sectional area, mass and stiffness in this place. These swords usually had a total length in the range of 1180-1250mm and a total weight of 1600-2200g. However, in the group of later ridge swords, this relationship is completely different. The most common range of distal taper for a long sword with a ridge is about 8 to 4 mm, but it varies greatly, depending on the width of the blade (the narrower the blade, the thicker it is at the crossguard). However, swords with a ridge but with a flattening are not so thick (about 5 or 6 mm), without losing stiffness due to the hexagonal section (the surface area of the section remains the same, the angles change).
Another interesting observation is that falchions preserved in museums, whose blades are narrow at the crossguard and wide at the tip, most often become thinner sharply just behind the crossguard. In the place where the blade is narrow, the stiffness is given by the thickness (4-6mm), and where it is wide, quite thin (about 2mm) is enough. Of course, falchion blades are slightly different due to the asymmetry and different proportions from swords. But the principle of stiffness and the relationship to overall weight and balance remain similar.
(for example, the Thorpe falchion has a blade thickness of only 2.5 mm and not much distal taper, but the Conyers 7 at the crossguard and it thins out raptly to circa 4 mm just behind the crossguard).
In turn, a longsword dating from 1380-1430 in the museum in Nysa, Poland, in excellent condition, is only 4.3 mm at the crossguard, weighs 1775 g and is 1134 mm long, having the bladew width over 50mm at the crossguard. We also know about 10 similar museums from other museums in this part of Europe and there distal taper is really minimal. However, some of the typologically similar longswords from the Czech Republic catalog contains also this type longswords with 7 or 9 mm at the crossguard and weigh similarly.
Some Oakshott Type X, so-called Viking era swords, have even 2.5 or 3mm at the crossguards and almost no distal taper to the tip. Others, in turn, have twice as much and thin out to 2 mm. It is also difficult to talk about any pattern defining standards, especially suited to all types of medieval swords.

What is a 'good sword' then?

Good sword properties, in terms of dynamics, weight distribution, correct deflection, good handling, are always a correlation of many parameters such as: weight / balance / distal taper / type / cross-sectional geometry / proportions / vibration points.
These are many complex variables and they all fall within certain ranges known from the measurements of the original swords.
But who/what decides which sword is 'good' and is this a valid consideration at all?
Since each person is different, has different strength / mass / dynamics / speed / fitness / age / experience / tactics, etc., maybe these criteria will be different for each of us? Personally, I think yes, it will always be a subjective judgment, within certain ranges. We learn this by examining and examining original swords, each of which is different despite its general similarities. It's similar with people, or in this case sword users.
Another aspect may be variable demand. Over time, we gain experience and change the way we use it. This is why, for example, we have several types of the same tool (e.g. a hammer or a knife). It was similar with swords, because sometimes people had several of them. Absolute standardization is not possible when it comes to medieval swords. A wealthy knight in the 14th century could have several swords, e.g. one for ceremonial purposes, the second for everyday use, the third for military expeditions, the fourth as a spare just in case, the fifth as a hairloom, etc. and each of these swords could be different and each of them was, in his opinion, a 'good sword' for its purposes.
Today we analyze all these swords using scientific standards, describing the same parameters and trying to define the ranges defining a given type of sword. This works if we consider the broader context.

Maciej Kopciuch, 2023 / 2024

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