Bec De Corbin - An example of Medieval Engineering
Initially inspired by the work of 'the upper class' a netherlands metalworker, the bec de corbin seed had been sewn...a must have for a medieval reenactor whom understands mechanical engineering. A quote request was sent to the company, however without a reply it soon became evident that if procurment of such a 'Bec de Corbin' was to be made, then it would have to be constructed.
The extremely interesting reference used for assembly of such pollaxe style weapons was Talhoffer. The illustration shows what appears to be serveral threads cut into the steel (nearest modern profile equivlent would be an ACME thread, althought this may just be artistic licence), allowing the components to be assembled with tempary fasteners. Interestingly the Talhoffer illustration shows two alternative components allowing the pollaxe to be configured (maybe this was intentional, or maybe conincidental), this suggests the threads are used as a non-permenant fastner. Certain engineering laws apply to this kind of assembly if intended as the only fastening method, these are maily torque and friction, and with use the shock and vibrations occuring from use, may cause the threads to self-loosen, somthing which has been overcome with certain threads using a secondary threaded item passing through the first (a form of a locking thread, simular to that of a modern cotter pin, or indeed a lock nut).
It can be seen that the base compoenents have secondary threads located to lock the components into place, however the head does not have such locking devices and therefore is dependant upon the thread to prevent the head from coming loose.