Is there anyone that produces differential tempered EUROPEAN swords ?
( slightly off topic ) And, Would filling the fuller of a sword with a similar clay as used in heat treating Japanese swords work as a technique to increase this differential tempering effect ? Maybe leaving the edges at 52 to 54 R.C. and with the center of the blade in the 40 to 45 R.C. (Just guessing here as to the numbers.)
Any idea if European swordsmiths ever used this technique ? Or did they use different ways to get a similar effect. I have seen a tool that resembled a tong that perhaps was used to apply heat to the center of the blade to retemper it. This would be done by heating the ends of the "tong" hot enough that touching the fuller of the blade would turn it blue quickly. You need to do this on both sides simultaneously, then need to cool immediately {water}, or you risk softening the edges too.
Doing something like this gives a hard edge, and a softer body. Today, Tinker does something like this to "differentially temper" his blades, and he comes up with an edge of 58 to 60rc, and a body of 46 to 48 rc. This also gives you a very different product than traditional differential hardening, the Japanese way.
Even without the antique tools, differential tempering makes sense. We know that many of the older antiques exhibit varying hardness', and we know that many of them exhibit a springiness to them. Pearlite isn't overly springy, its tough, tends to bend {take a set} relatively easy compared to the same crossection martensite.....
We have texts from the 16th C about the tempering of steel and those show us that there was a developed understanding of the effects of heat, cooling rate and degrees of temper of steel. Although there was no concept of carbon content.
Steel used varied as well. From the rather crude to material of very high quality.
When heat treating simple carbon steel, and especially in a very fine grain structure (as you would want in a sword blade) the ability to harden gets pretty low. That means you will have to cool the material very quickly to get any martencite at all. The martensite you get will also not go very deep. How deep depends on carbon content, grain structure, quenching medium, shape of cross section of the blade, mass of the blade and amount of heat to remove. Knowing this, it becomes pretty obvious how meaningless it becomes to speak about specific effects of "medieval" methods and apply these in a very general way. There are simply too many variations to take into account.
What we can see is that a simple "monosteel" blade of diamond cross section will just as a result of its cross section get a variation in hardness from the edge to the spine. The core will also show a mixture of pearlite and bainite in a thick blade. It is like a skin of varying thickness with martensitic structure (hardened) around an oval core with a less hard structure. In a thinner blade the base might have this mixture of "unhardened" material in the core, while the outer section towards the point gets hardened all the way through. Please not this need not be the result of lamination of iron core, steel surface: a monosteel blade of simple carbon steel will show this variation of structure trough out its length and thickness. This is a result of varying cooling rates of different parts of the blade.
You do not have to play with differential temper I know that the vikings did write runes on their weapons to make them more effective in combat.
Alu is a Germanic charm word appearing on numerous runic inscriptions found in Central and Northern Europe dating from between 200 and 800 CE. The word ? the most common of the early runic charm words.
The only local weapon that has a runic word written on it that i know about was found at Øvre Stabu farm at Eastern Toten, Oppland, in one of two graves, a 28 cm long spearhead with a runic inscription was found. In the grave they also found other weapons and fragments of weapons, more or less damaged by fire and corrosion. The tomb and the inscription are dated to the last half of the 200's AD. Thus it is one of the oldest runic inscriptions in Norway.
The nSl. word raunijaR is similar to the gno. reynir, which means "one who tries". raunijaR might be the name of the spear.
A good deal of Norwegian futharcs and some inscriptions:
Here is some of the shapes a viking battle axehead had.
a Skjeggøks (bearded axehead ) :Steinsvik, Nordland
The blade on the axehead itself was reasonably light and forged very thin, making it superb for cutting. The thickness of the body above the edge is somethimes as thin as 2mm. Many of these axes were constructed with a reinforced bit, typically of a higher carbon steel to facilitate a harder, sharper edge. Average weight of an axe this size is between 1 kg and 2 kg (2 and 4 pounds). Proportionally, the long axe has more in common with a modern meat cleaver than a wood axe. This complex construction results in a lively and quick weapon with devastating cutting ability.
Based on period depictions, the haft of a Longaxe for combat was usually between approx. 0.9 m and 1.2 m (3 and 4 feet) long, although Dane axes used as status symbols might be as long as 1.5 to 1.7 m (5 to 5 1/2ft). Such axes might also feature inlaid silver and frequently may not have the flared steel edge of a weapon designed for war. Some surviving examples also feature a brass haft cap, often richly decorated, which presumably served to keep the head of the weapon secure on the haft, as well as protecting the end of the haft from the rigors of battle. Ash and oak are the most likely materials for the haft, as they have always been the primary materials used for polearms in Europe.