[TheForge] quench questions

[Andrew Vida]

David E. Smucker wrote:
> It is always a good discussion on "super" quench, (I wish it was called 
> "rapid" quench, keeping in mind that there is no magic at work here.)  
> Best data I have seen to date is that with small section (1/2 x 1/2 
> square A36) you can get to a Rc of 50 or so.  An that is without any 
> drawing or tempering.

	That would seem about right.  I've made quite a few tools from A36... 
punches and chisels... and for the most part they have worked well. 
Most I made as throw away tools, only to find that they were too good to 
toss adter use, so they went into the handy bits bucket.  For quick and 
dirty tooling, I don't think you can beat it.
> 
> In large sections such as a hammer die or even a hammer die insert would 
> someone please explain the physics on how you will quench this rapidly 
> enough to get a hard surface let alone any depth of hardness. 

	You may not be able to.  dies for a typical 25# hammer may work out OK, 
but I'm not at all sure that anything bigger would.  The only thing I 
can think of is if you had perhaps a couple hundred gallons of the 
stuff, had an enclosed area with hose and pump, donned a space suit and 
exposed the work to a violent jet of the medium, which I would expect 
would harden to a case at best... maybe 1/2 to 3/4 of an inch? But that 
might be just good enough. That's just a guess based on what I know 
about the materials.  For all I know, it might fail completely... or 
maybe do even better, though I doubt it.

I agree with you that just using a good plain tool steel is probably a 
much better bet.  4140 isn't that expensive, comparatively speaking, and 
the headaches saved, I think, are well worth the few extra dollars. 
Some things just are not worth rigging if you don't have to.