Better plate connection

[newts]

My plates are only stuck on to terminals with a silicone adhesive
How deep can I drll into terminal post to add a self tapping screw . Or can you suggest another fixing method.

 

[newts]

I forgot to add my name, ?
Allan ref

 

[Pir8Radio]

I would include some info on the batteries. Maybe someone is familiar. Or just go for it... I would imagine you are good for at least 1/4 inch then tap them (fine thread) rather than using self tapping screws, just because they have the wasted non threaded space at the tip you want as much thread grip in that 1/4" as you can get, washer to hold the plate down.