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Origin of Hex Head Nuts/bolts?
(Stan Schaefer) wrote in message . com...
"CWLee" wrote in message ...
Can anyone here point me toward an authoritative history of
hex head nuts and bolts?
Hand-forged
wrought iron nuts and bolts were probably easier to make with square
heads.
That is correct, on old farm machinery etc. nearly all the hand-forged
nuts and bolts I've seen had square heads.
We have several old hand- and horse-drawn wagons/carriages that all
are held together with have square-headed nuts and bolts, but that
have hex-head wheel nuts since you can fit a larger hex- than square
headed nut into a round hub.
These are all obviously handmade fasteners, and apparently the maker
only made hex heads when he really had to.
By the way, those wheel nuts have left- and right- handed threads
depending on what side of the carriage they are for, so that they
won't unscrew themselves during forward driving. This in addition to
locking pins and, in some cases, opposite-threaded, smaller diameter
castellated locking nuts. Apparently, wheels coming off at speed was a
Serious Incident, and some rather ingenious engineering was employed
even on cheap, otherwise low-quality wagons. I've never seen such
opposite-threaded nuts on modern carriage axles.
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