The manufacture of swords
I shape all sword blades by hot-forging. In this way only slight grinding and polishing are needed to finish the blade.
The mid-sections of pattern-welded sword blades are forge-welded from pattern-welded rods, which are constructed from alternating layers of iron and steel. The bevels of the blades are made from better-quality steel, and they are welded separately in the patterned mid-section. After all welding operations the blade is forged to shape.
The surface of a pattern-welded blade is etched with a mild acid to bring out the patterns. Non-carbon iron remains bright whereas carbon-rich steel is coloured dark.
Ferrous inlays on sword blades have been made from thin, layered pattern-welded rods. All letters and marks are sunk into the blade or its blank by hammering, after which they are permanently attached by forge-welding. Finally the blade is forged, ground and polished, and the inlays are made visible by acid etching.
All blades are quench-hardened after forging and before the final grinding and polishing. This creates a hard cutting edge. In quench-hardening the hot blade is plunged into oil or water, causing the blade to cool very rapidly. This in turn creates a hard and fragile crystal structure in steel, which has to be softened and stiffened a bit by tempering it in a lower temperature.
Some reconstructions of Viking Age swords exhibit iron hilt parts, which have been decorated by non-ferrous inlays from copper-alloy and silver wires. These wires are hammered into cut grooves, after which the non-ferrous surface is smoothed and polished, hiding the iron underneath it.
One technique to cover iron surface is to overlay it with non-ferrous wires or thin sheets. The iron surface is napped with chisel, and the wires or plates are hammered into this rough surface.
Bronze hilt parts are made by casting, either by lost-wax method or by sand casting.
Viikinkimiekat Suomessa (2018)