Hornbeam

[Delwin D Fandrich]

Newton Hunt wrote:

> > Some years back I compared maple hammershanks to hornbeam shanks directly,
>
> Was the hornbeam shank turned down to the same diameter as the maple?
> A hexagonal shank will be inherently stiffer.  Even _I_ can _feel_ the
> difference in the more ridgid hornbeam.

As close as they could be, yes.  The hex shank is not inherently stiffer than a
round shank of the same relative diameter.  The best shape for hammershanks, of
course, is rectangular.


> Shanks are thinned in the treble to reduce weight.  It should not
> effect flexibility in the vertical plane much at all.

Thinning shanks to reduce mass does also reduce stiffness in the vertical
plane.  It is generally considered to be an acceptable tradeoff considering the
lighter mass of the hammers involved.


> Would the payoff justify the expense of getting different wood?  One
> uses the resources one has so european manufacturers use local woods,
> just like we do.

I don't know.  I just don't like being told something is better for me when the
actual reason(s) are something altogether different.  In this case the primary
reasons for using hornbeam (beech) instead of hard maple are cost and
machinability.  These are not bad reasons.  I'd just like the manufacturers to
be upfront about them.  And I would like being given the choice.  In the
meantime, we use shanks being made from hornbeam.  And I do appreciate their
overall quality.  They are certainly an improvement of the slop we had to put up
with before Lloyd started importing Renner parts in a big way.  I'd rather live
with the limitations of hornbeam than poor machining quality and sloppy
assembly.

One advantage I don't see being touted, by the way, is that because of the
density consistency of hornbeam it is easier to drill a straight centerpin
hole.  This is what helps to reduce the amount of traveling required in the
finished shank.  It is not impossible to do a good job of this using hard maple
but, because of the greater variation in density between early and late wood, it
is more difficult.  You have to use a bit of care in selecting the wood and in
orienting the grain.  And, you actually have to sharpen (or replace) the drill
bits more than once every year or so whether they need it or not.  (Some years
back I actually watched an operator (knowingly) using a broken bit to drill this
hole.)  And you have to be sure the drill shaft bearings don't have half a mm
run-out.

Del