poor quality choc blocks

I've just used some 5A junction boxes from Toolstation where the screw heads snapped off at the first sign of tightness. Fitted five - happened on three - always on the terminal used for earth.

Yup there are some really poor ones about...

Ages ago I bought bulk packs from TLC, and they're ok but not brilliant. Where would you guarantee to get top quality ones?

Don't know about guarantee - you never know when someone is going to change supplier.

Normally I get them from CPC and they have been OK so far.

Same here, and they have different types to choose from. They often have the 30A ones going cheap in their leaflets.

Has anyone got a good source of the type with an flat insert in the hole? This is pushed down onto the wire by the screw to grip the wire.

I used to use these for connecting thin stranded wire where soldering the strands wasn't a good idea. The standard one where the screws rotate down into the wire are no use with such fine strands

I've taken to fitting bootlace ferrules, but that's one extra operation

- and cost...

Back to the original topic - I've recently had some choc blocs locally sourced that have had such a long unthreaded part and a dome on the end of the screw such that it was held by no more than a turn or two of thread when tightened onto the wire. Tightening it up resulted in a stripped thread...

Leaf protection springs -- yes CPC again ("Protectors" in following)...

Thanks - the link through to the maufacturer, Camden Electronics, has provided some other bits I'd lost the source of, e.g. the pluggable type. Their terminal strip looks to be of good specification, having heat resistant plastic, plating of the brass parts, captive screws - and stainless "protectors"

As I said I bought bulk packs from them ages ago - 5,15 and 30 amp. Not even sure they were all of the same manufacture. Quite a few of the 5 amp ones have non existing threads or whatever - the screws go round without tightening up. But restricted to the odd one on a strip so you just don't use that one.

More annoying are the screw heads. Meant to be those types that will take either plain or crosshead. But no screwdriver I possess is a good fit in either. Basically, the indents are too shallow.