dt gk 24/6

[straydogs]

9D Process iron so that its outer surface is converted to toughened steel 4 - 6

? a ? e / ? a ? d ? n

[shammydodger]

face-harden

[Clanad]

Also possible is case harden...

[straydogs]

Thanks shammy dodger I would have never have got that!!

[straydogs]

And clanad too!!

[wooleyback]

i teach wood occupation at college, case hardening is the amount of water left in TIMBER and can be dangerous if machined therfore i dont think thats the answer

[shaneystar2]

Definitely case harden
http://dictionary.reference.com/search?r=2&q=c aseharden

[wooleyback]

hand it to you shaney. But the defect caused by the amount of water left in timber after it has been dried is refered to as case hardening. I have been teaching it for twenty years and i did not know i was an engineer, i will never live that down

[Bordeaux]

Not sure where TIMBER part comes in here as the clue stated steel, and case harden was given as the answer on 24/6.

[Brooksy]

Having restored classic car engines for 30 years, I can confirm that it is "case hardening".

[wooleyback]

my fault bordeaux, i noticed second answer as case hardened and being in wood assumed it to be wrong