there isn't any UK techie sites as good as this one though unfortunately
Check out
Blue Room technical forum (Powered by Invision Power Board) - I'm fairly sure I'm not the only person here who frequents that forum as well!
Back to the hookclamp (
G-clamp) debate; they're standard in New Zealand as well as the UK, much more so than the
Altman clamps. They usually come with a
SWL stamp of 50kg - at least all ours do - and they don't
bend at all easily and you can lock them off very securely. If you hire a Mac250 down this end of the world, it'll generally come with two hookclamps to suspend it by (although the bigger moving units will have cheeseboroughs or half-couplers usually) - and I've never seen one fail, nor even heard a story of one failing. The thing that I like about them is that once one is on the bar, it can't slide off like an
Altman can - whenever I'm rigging something with an
Altman, I'm always (probably through unfamiliarity!) worried that before I've tightened it up, it'll slip off the bar....not that it's ever happened to me! To answer the original poster's question, we tend to run bolthead, washer,
yoke, washer, clamp, washer, spring washer, wingnut. Occasionally on the heavier generics (big profiles mostly) we'll use an M12
bolt with a regular
nut, but all the rest are M10 bolts with wingnut. We do buy bolts of the right length to do this though, so that you can get the clamp over the bar - occasionally some of our units still have old bolts in them which are too long and so then we turn them up the other way - or just loosen the
nut off a
bit, get the clamp on the bar and then tighten it up again!