[TheForge] Treadle Hammer Anvil Stand

[xlch58 at swbell.net]

Bruce Freeman wrote:
> What matters is the overall weight of your TH anvil.  I vaguely recall
> a recommended hammer-weight to anvil-weight ratio of 1:5 or 1:10.  So
> if your TH hammer is, say, 50#, you want an anvil of at least 250#.
> 5" square x 36" tall steel is ~250".  6" round x 36" tall is a little
> more.  Hence, skip the stand and just use a vertical piece of steel.
>
> Bruce
> NJ
>
>   
Sorry, I have to disagree.  Mass is not mass when it comes to anvils.  
What matters is maximizing the contiguous mass directly in line with the 
hammers blow.   I have noodled over the dynamics of anvil and hammer for 
as long as I have had both.  After many years I found an older book 
about stress wave propagation in solid materials, which was a difficult 
read, but I think pointed the way for me.  Since then, I have had the 
opportunity to see some finite element analysis of stress wave 
propagation from impact (generally bullets, but sometime something more 
prosaic)  If the material is contiguous, then the impact will reflect 
back directly and there numerous secondary impacts as a result as the 
system "ringing"  If there are discontinuities, then the reflections are 
refracted and not as much energy goes into the secondary impacts.  This 
is why vertically oriented material does better than welding up 
horizontally oriented material, though solid is still supreme.  

Charles