Pirate warning tom Davies
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SUB-STANDARD "pirate" locking jaws in circulation for fifth wheel couplings are worrying Davies Magnet.
The Davies jaws are twin steel forgings which encircle and retain the trailer king pin. Pirate jaws examined were more roughly finished and their machined faces did not always align properly.
Davies Magnet's jaws, machined in pairs, are kept together throughout the production cycle to maximise the effective bearing area.
The loading plunger on the pirate jaws is sometimes slightly wedge-shaped instead of rectangular which could make it difficult for the driver to lock the coupling.
Genuine Davies Magnet jaws have "132190" forged adjacent to the boss for the pivot pin and matching pairs each have a two-digit code stamped on both sides.
Metallurgical analysis of the pirate locks has shown that they are not forged from the same materials as the original parts.