Search the Community
Showing results for tags 'wolfs tooth'.
Hello all! I'm very excited to share some details of a recent experiment in recreating a historic wolf's tooth pattern with Emiliano Carrillo and Luke Shearer. The general goal was to try and recreate the similar tooth shape, depth, and spacing as found in historic pieces, mainly referencing the spear found in Lapland (p.151 in Swords of the Viking Age). All of the steel used with exception of a bit of old wrought iron is home made, and there were a few things we learned specifically because of this which I'll get into. Because I took a copious amount of photos, this'll have to be a few parts, so bear with me! The first thought was to use a rack to press into a bar with which to form the teeth. Based on the tooth shape having a slight trapezoidal profile on one side, it seemed like the perfect fit. The above bar is 8 teeth per inch, and in person looks like it would make a nice tight pattern. However, the depth is too shallow and the spacing too tight. For reference of what that looks like in steel, look at the below sax blade that we made as a test piece. There is a faint strip of wrought between the twists and the edge, and although difficult to see at first it has a slight wiggle. Part of the problem with the rounded bits is that the blade was drawn out a little during forging, and even that deformation was enough to turn the squared corners into a sort of sinusoidal deal. Due to the spacing, another reason that this is not ideal is that the cut depth of the teeth is too shallow to reasonably achieve with a chisel without bending the previous teeth over and closing the gap. That leaves cutting them with a hack saw or modern equivalent, but looking at the originals the continuous grain patterns are mostly suggestive that they were mostly not done that way (not to say that some of them couldn't have been). The next one we tried was using a 6 tooth per inch rack. The spacing and depth is much closer, but still too tight for the reference spear. I would expect this to work better than the 8 TPI rack because of the extra depth making the weld more resilient to shape changes, but we wound up discarding this due to its size and regularity. Also, the rack forms a sort of positive die where we need a negative one. The wrought almost universally has the flats in its troughs and the edge bar has points in its troughs, the opposite of what would be formed by pressing the rack into the edge billet. While you may be thinking that we could simply press into the wrought instead, I do not think that is how they were made for four main reasons. First, the wrought is incredibly thin (not from grinding) where it joins with the next inward bar, and would not be strong enough to support being used as a die. Second, the wrought itself is fairly soft compared to even a hot edge bar, and the teeth would deform opposite how it appears in the historic patterns. Third, the tooth points are sharp in the wrought, which is very suggestive that the edge bar started with a sharp groove that the wrought filled into, which is reasonably the order it must have been done given the available technology. Last, the grain of the wrought in the teeth is very obviously continuous in most cases, which means the forging of a toothed bar at such regularity would be absurd with the relative ease of instead notching the edge bar... All that is the long way of saying that we abandoned the racks and went to something else. To get the spacing as accurate as possible, we took a 1:1 scale print of the Lapland spear and measured the tooth spacing. Because of the other indications in the pattern, I found the sections which would have been drawn out the least by subsequent forging and averaged the geometry from the two halves. The final result is a hair under 4 TPI and a depth of 4mm. On the test bar, all of the teeth were cut based on the tooth previous so any error doesn't compound and gradually increase the size the farther down the bar. Doing this enough, it would not be difficult to maintain an acceptable accuracy doing it freehand, which eliminates the need for dividers. With the lines scribed, I took a cold chisel and cut just enough for there to be an easy surface to register against. The idea is that these lines are just a guide for a hot chisel. And finally, cleaning it with a file for the sake of being tidy. Not necessary, and again another thing that would not be needed to do this with a more limited toolchest. Next post will be how we handled cutting the teeth with a three man striking team. John