California, USA - Niels Provos in shows how to upcycle an antique iron tyre into a handmade sheath knife. The video shows the whole process, cutting the rim into chunks, forging them with a power hammer, melting in a crucible, forging the ingot into a steel bar - where Niels can tell the carbon content from the number of stars that form during hammering - through to the finished knife.
As he says, "Finally everything is put together and you can marvel at the carbide grain structure of the blade"
Neils deals with viewers querying tempering embrittlement, martensite (a hard form of crystalline steel) and wootz (a crucible steel characterized by a pattern of carbide bands) in the comments section under the YouTube video. Wootz steel originated in India in sixth century BC (see the second video link below).
YouTube: Making a Knife from Wrought Iron Wagon Wheels: Recycling History
YouTube: Wootz and the sword of Tipu Sultan
Story Type: Feature