max spade width for plastic covered binding posts

Does anybody know the max spade width that the plastic covered binding posts (like the WBT WBT-0710 Cu) can fit through the plastic cover slot?

I am trying to decide whether to use those shrouded binding posts?
I don't know, if there is any such standard. You should be able to find out for yourself with your amp, simply by looking at the amp you want to use. It should be obvious that at a certain width the spades either will not fit the space allowed by the amp or if the spades would contact each other
I have the same type on my Marantz integrated and I really don't like them. They're touted as top flight 5 way binding posts but they really limit the way one can hook up speaker wire. Bananas are the easiest, followed by bare wire (but it's so much easier threading from above than bellow, which can be very frustrating) and as for spades, you can only insert them from above.

If you are installing them yourself, make sure you orient them the way you like, if possible.

Mine can accommodate 1/2" spades but not all spades are equal. Any deviation from straight on either side of the tine can snag. I had a Dickens of a time trying to get an older pair of spade ended wires to connect. Some ends went in okay but others didn't.

All the best,
Those binding posts are driving me (to) bananas.

The ones with tabs restrict not only the width of the spade but the position at which you make the connection, and that position is often inconvenient or even impossible. They must have some benefit to someone, but are nothing but a bane to the hobby as far as I'm concerned.
Thanks peoples, after more checking it appears that a spade with a 13.5mm width can be used the plastic shrouded posts :)

Yes, they seem like quite a nuisance and maybe not a good idea. Bananas are definitely easier :)
I removed the plastic shroud from an amp because they were such a pain for spades. Very simple procedure.