Ref insrted edge - you guys must be sick to death of me going on about edge tools, but here is another instance of tool making technology that can apply to making swords and other weapons....
English scythe makers forge welded a sandwich of high carbon steel with a mild steel back between two pieces of wrought iron. This minimised the use of the more expensive carbon steel, gave a tough flexible body to the blade and protected the carbon stel during hardeneing and tempering. This technology continued up to the 1940's in Sheffield, and the 1960's in Belbroughton.
See
http://www.youtube.com/watch?v=AqV3jtkQSe4 for the Clay Wheel Forge in Sheffield - a similar DVD/video of the Nash Works can be obtained from the Belbroughton History Society....
Other makers such as Elwell used their own rolled 'sandwich' and even offered it for sale to other edge tool makers..
Billhook makers also used the same methods in both France and the UK, although more commonly a high carbon steel was face welded to a softer body, giving a very pronounced weld line... Axe makers tended to insert a steel bit into the body, a method also used in the vineyard hoes of Bernard Solon (Maison Alexis) in Orléans, France
http://philippebachelier.com/Portfol...rtraits06.html or
http://dytic.over-blog.com/article-d...-59608149.html there is an article in a french blacksmiths' magazine showing the stages in the manufacture - I do not have the web-link handy, but he won the annual prize for his work a few years ago...
The weld line clearly shows in the edge of the currier's knife made by Alfred Green (UK) and the difference in patination on the William Swift (UK) billhook, and very clear on the French billhook blade..