Durability of a tin coating on belt parts

[Latinitas]

Could anyone with more practice experience tell me how durable tin coatings (the ones applied with tin-it 40/60) on belt parts like buckles, frogs and plates are? For example: on the attached buckle from my own collection, the red line indicates the place where a lot of friction will occur between the leather and the thin tin coating. Considering the thinness of the coating and friction, one can expect that the coating will become worn out pretty fast at such places. How long is the coating expected to survive? Could anybody give an indication of the durability?


And as always: English is not my nativa language, so my grammar could be somewhat incorrect.