Yeah it's just a cheap home gym type bar. When I bought it 15 years ago I asked the guy how much it could take and he said "more than you could handle". I took that to mean it was probably 800lbs or something. Not 330, the cheeky fucker.
The new bar I'm looking at is good for 700lbs which should do me for a while (probably the rest of my life). If I ever get to the stage where I'm lifting over 700 I'd be thrilled to have to get a new bar!
The plates are standard 450mm diameter.