The pictures show regular Molex KK series (or similar) parts (housing
> and receptacle pins). No part numbers, and it's not even obvious
> whether the purchased product is PCB mount or wire end crimp, male or
> female pins, or male or female housing (plug/header)!
>
> Is that Jaycar in short? -- a bunch of ambiguous or store-rebranded
> stuff? The equivalent of Tandy/RadioShack (at least, in the days when
> they sold parts like this)?
>
> I haven't had problems with properly selected and mated Molex KK
> connectors. Perhaps yours were not correctly fitting, correctly cut and
> inserted, etc.
>
> The single-wipe spring contacts in that type of connector can be easily
> bent, if overly large pins are inserted, or the socket is flexed over an
> incorrectly designed header (no keying/retention tab). They can also be
> easily bent back by pushing a dental pick in from the wire side.
>
> I guess I would also ask, why would you buy from anywhere but a
> thoroughly detailed supplier like Digikey or Farnell? Connectors are
> notoriously hard to shop for as it is, let alone if you're trusting in
> whatever some low-tier distributor decided to put in their catalog...
>
> If you're looking for wire ends to mate with 0.025" square posts (0.1"
> pitch, 0.23" typ. mating length), I would suggest Molex C-Grid SL (no
> polarizing/retention) housings with the socket type (crimp or IDC) pins.
> These sockets grip the square pin instead. They're also recognizable as
> the generic rectangular headers/housings used with e.g. desktop computer
> front panel lights, etc.
>
> Tim
>
They used to be much better than tandy or radioshack. Now, I'm not so sure. I would say still better, but it is much closer now. Very sad for Oz hobbyists.