Whimbling iron

A whimbling iron is a bell clapper made from ductile iron [http://www.ductile.org/didata/default.htm] . Traditionally bell clappers were standard cast grey iron iron with a razor like chrystalline structure that lead to sudden catastrophic failure over time. The standard clapper is distinguished by the experienced ear as a whefting iron. Whilst some believe that the advent of "health and safety" lead to the search for an alternative, it is more likely that the ability to forge the bottom end ready for use practically died out early in the second world war. Some attempts at composite clappers were made, but the advances in casting technology driven as much by the motor industry as by the war machine resulted in the adoption of spheroidal graphite iron castings [http://www.key-to-steel.com/Articles/Art21.htm] . Ford Motor Company adopted the material for petrol engine crankshafts in the 1950s as a cheaper alternative to steel.

Whimbling Iron has passed into the colloquial Yorkshire dialect referring to any tool (incorrectly) used as a hammer. Usage is moreso within the Mercian sub-dialect - no coincidence that Halifax and Leeds are amongst the few places in the UK with a still functioning true ring of 12 [http://www.bellhistorians.org.uk/modality.htm] (Croydon and Great Yarmouth being others).