Olivier Den Hartigh (asker) Mar 13, 2018:

Looks like might suggestion of a car battery might be right as rest of document suggests to bring - 4xM8 ring terminals and a suitable crimper
For secondary grounding:
Ring terminal crimper for the AC wire
Ring terminal
Serrated washer
Grounding screw
Two washers
Sorry everybody, I guess I should have provided you with more context

Olivier Den Hartigh (asker) Mar 13, 2018:

Hello and thank you everyone for your help,
Tony, you are making good points here. AC stands for Alternative Current, so I assume the stud connectors are designed to block the AC cable into position. I assumed on some type of stud, then the cable is somehow placed on a stud, a bit like the cables on a car battery, then the HEX connector is screwed onto the stud. Of course, this is just an assumption. I'll ask my client for a photo

Tony M Mar 12, 2018:

@ Asker (2) Note too that 17/32" = just over ½" = approx. 13 mm, which is quite a large size for an Allen key! This makes it all the more curious, then, that they should refer to this as a 'screwdriver' — in US English, this would more normally be referred to as a 'wrench'; this in turn could indicate a non-native writer, and perhaps they mean 'open-ended spanner — which is a plausible dimension (in fact, it might originally have been intended to be 13 mm!) and would be suitable for use on the kind of 'stud connector' illustrated in your ref. (which requires an external hex spanner, not an Allen key at all).

Tony M Mar 12, 2018:

@ Asker Please could you clarify with some more context? The 'stud connector' in your ref. is a mechanical joiner for 2 lengths of 'stud' ('studding) = 'tige filetée', but these screw directly onto the stud itself and so don't have fixing screws. As F-X has shown us, other types of stud connector also exist.
Do you know what the 'AC' stands for here? It might help if we had a bit more idea what field this is in: it could be AirCraft / Alternating Current / Air-Cinditioning, ....
In particualr, I think we need to know whether this is a purely mechanical or electrical component?
Note tlaos that this appears to be a US text (the dimension seems to be expressed as 17/32nds of an inch, a decidedly exotic dimension for a hex-head screw — note in passing that in this instance, it's quite possible this might be some kind of grub screw.