"Don Foreman" wrote in message
...
On 19 Sep 2005 22:07:37 -0700, "Bryan" wrote:

Whilst thinking about another problem, I find myself wondering, "why is
it that bolts have hex heads rather than octagonal or some other
number?"

Is there some wisdom about the history of this?

bmw

A guess: bolt heads were once square, requiring 90 degrees of
rotation before a simple wrench could be repositioned to grab another
bite. Machinery got more complex, spaces got tighter and access more
limited, hence hex requiring only 60 degrees of rotation between
bites before robust ratchet wrenches were available.

Note that the typical open end wrench is angled---so by flipping the wrench
over you can make small adjustments in confined quarters. It would not work
as well with a square head.

Harold