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Leatherface
10-18-2010, 04:31 PM
Hey guys

What is the proper thermal cycle for a tang that has been wielded??

I have a small hunting knife that I REALLY want to put some leather washers on and I need a threaded tang to do so...

SOO I gonna slot the tang and wield it

but

this will cause grain to grow

what should I do??

steel

1/4" 1084

Kevin R. Cashen
10-19-2010, 08:17 AM
You got the right idea as far as the grain size. I personally thread all of my tangs directly, not because I find any inherent weakness in welding so long as the weld is treated afterward, but because the belief in the weakness of welding is so prevalent that my customers feel better about the direct threading, and it is all about what makes the customer feel best. I have demonstrated welding threads on at hammer-ins, using proper follow up heat treatments, and then tried to break the weld only to have the tang or threads break instead, after multiple back and forth bends, but, of course, if you don't thermally treat that weld it will probably snap in one bend.

Here is what I would do-

I like to use a torch to weld the threads because of the preheating effect, but I may use my TIG if I had to do it these days.
Weld the two pieces together and then allow them to cool before reheating the weld zone to nonmagnetic and then allow to cool again
Next reheat at least twice to nonmagnetic and then quench to cold in a good oil.
Follow the quenches with a heat to dull red a couple of times. Let it air cool and then get to work on cleanup.

Leatherface
10-19-2010, 04:34 PM
Kevin
thank you sir for your response

Would you preheat the oil (145 degrees) before the quench or do a room temp quench like you were doing a normalizing cycle on over heated steel?

thanks again bro I do appreciate all that you do

Kevin R. Cashen
10-19-2010, 10:45 PM
It is not as critical for the oil on this quenching as it would be for the actual blade hardening, the idea is to cool the steel quickly to promote fine and even structures, not necesarrily to achieve maximum hardness.

Leatherface
10-20-2010, 04:55 AM
WOOHOOO thanks again bro!

SteelSlaver
10-27-2010, 06:49 AM
It amazes me the people who will buy into forge welded blades that will reject the idea of having a electrical process weld in the tang area. Some even go so far as to believe that soldered or mechanical connections are better. Thanks for weighing in on this Kevin