Table of Contents Introduction Texture From Impurities
Texture From Natural Structural Heterogeneity
Wootz or "True" Damascus Steel: Persian Kirk Narduban
Coarsely Laminated Steel
Pamor of the Malay keris
An Indian Chevron-pattern Talwar
Finely Laminated Steel
Hada (grain) of the Japanese sword
Hamon from differential heat treatment in Japanese blades
Patterns From a Piled Blade Structure
Philippine Barong, an Indian Naga Dao and a Celtic long sword
"Mechanical" Damascus Steel & Pattern-Welded Steel
Structures from twisted, piled rods as seen in a yataghan and a Viking sword
When we look at modern industrially produced iron and steel, little or no texture is readily apparent without magnification, even when the objects have been corroded. Earlier iron and steel artifacts will frequently show a pronounced grain structure, often due to impurities banished from or tightly regulated in modern materials.
In the case of antique edged weapons, the smiths frequently manipulated the grain properties and joined together dissimilar materials to achieve desired performance and/or appearance. Such patterns often yield clues to how such items were made. This presentation, expanded and revised from the introduction of a lecture on pattern-welding presented at the 1990 Ashokan Seminar of the New England Bladesmith's Guild, will show a sampling of such patterns as are found in swords and other edged weapons from a diversity of cultures and times. The classification of techniques below admittedly suffers from being somewhat artificial and arbitrary.
In viewing the following series of examples it is recommended that the reader consider four dimensions, as all will be present to some extent in many examples. First, the natural grain background of the material, such as that arising from slag inclusions like those seen in wrought iron or from natural crystalline structural heterogeneity as in wootz steel. Second, grain structures enhanced by the bladesmith in layering and folding the raw material back upon itself either few or many times, and whether solely for mechanical benefit or for deliberate aesthetic effect. Third, forging effects and manipulations undertaken by the smith to distort the background natural grain and the layering to achieve the desired pattern. Also important to consider in this dimension for the layered structures will be the planes of subsequent stock removal (grinding) and how they intersect with the grain and layer structure to form the visible surface pattern. Fourth, the further effects obtainable in a blade made up of several components welded together, whether it be piled structure necessary to achieve the desired blade mass and perhaps never intended to be noticed by the customer or deliberate decoration such as the lengthwise twisted rods in a classic pattern-welded blade such as a Viking sword or yataghan. The probable extreme in the welding together of many components is exemplified in a chevron-pattern Indian talwar.
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