Sun umbrella parts

[chris]

Does anyone know where I can get a 'locking' washer for my garden sun umbrella. It is a 1.8 cm diameter but 2.5 cm at the widest point. It has a bar across the centre which fits in the screw end and 2 small tabs on the sides which can be raised to lock the bolt in situ.

[Dean Hoffman]

Take a look at your local Ace Hardware Store. Would some sort of a locknut, maybe a half nut, to the job? Maybe double nut the whatever?