Hardening metals

[Chris152]

Having recently been searching for turning gouges and wondering about the different kinds of steel used, I started wondering about how the metal is hardened and things like that. By chance I was reading Theophilus's 12th century book On Divers Arts on Saturday evening (as you do) and noticed the following, which helped clear things up for me.

 

[Steve Maskery]

I note that the treatise does not say whether you have to treat the small red-headed boy in the same way as the goat...
Excellent find!

 

[Geoff_S]

Where is the emoticon for gob smacked?

Brilliant!

 

[profchris]

Oh dear - all my goats are under age for this.

 

[Racers]

I think he was taking the pi55!

Pete

 

[--Tom--]

AFAIK Saline solutions make for a more severe quench (less of a vapour jacket) so you can get a bit more hardness from water quenching steels

 

[Phil Pascoe]

I wonder whether a two and half year old goat would do? Surprising how little English has changed in 900 years.

 

[flh801978]

What sort of materials would they be hardening in the 12th c ?

 

[Steve Maskery]

What sort of materials would they be hardening in the 12th c ?

Iron, presumably. Copper and lead are soft, steel had not been invented. What else was around then? Lead, tin, bronze. I wonder if they even needed to try to harden bronze? We still make bearings out of the stuff today, don't we?
Good q!

 

[flh801978]

You can heat and quench iron as much as you like it won't harden

 

[MusicMan]

Correct, it needs carbon. This was mainly available through case-hardening, which has been in use for several hundred years at least. It was used for samurai swords in Japan in the mediaeval period.

 

[jim1950]

all very interesting, but after 50years I find out why the firms blacksmith always had a stinking bucket in the corner of his workshop
I was thinking he just did not use the wc

 

[CHJ]

I think the subject has been discussed before from time to time.

 

[Brandlin]

I've always suspected that the idea of "Magic swords" came from a sword that may have been made with more carbon inclusion. Either by a lucky blacksmith/armourer or one with closely guarded secrets. The sharper more durable blade being thought to be special by those not in the know.

Any sufficiently advanced technology is indistinguishable from magic.