Safety Pin A
Flushed type with dovetailing the fixing method is only friction, it is risky and not recommendable. What if a Gasket is inserted in between? With molding, dimension is never precise. Even with gaskets, some could be very loosen because of the temperature difference. Extra piece molding fee is 4000 Euro.
Safety Pin C1
No pin, just a bump
(Clearance is 0.1mm for tightening)
Slight bump is necessary even with safety pin. It will let users know where it reaches by clicking.
Mateiral of Simple safety pin: PC is recommended. Gasket (like rubbers) types are too flexible to put in. Hook(of narrow step) in the end for clicking is preferred for every stable fixing. Also, a hat for easy take-out is also necessary. Instead of molding, Lathe machine (Turning cutter)is the solution.
1000EA/800Euro
Consequence
A combination of pin and clicking bump will guarantee a stable closing and easy opening. Also, it makes the mold design loads reduced since the clicking bump is not requiring fine dimension manipulation.