Any question answered...

Well it used to fit my bb tool (32mm) and has plenty of leverage, you can see why i gave it a try. I've use it successfully many times in the past. I don't have a large enough adjustable spanner or a vice. Time to get one.

Oh I see, I thought you were using it for a fixed cup of a traditional bottom bracket. If you are using a BB tool for a cartidge BB. You still need to use a real spanner (not a flat spanner). The vice would be excessive in this case. Get yourself a bolt to help secure the BB tool against the BB. Then use a large spanner (available in a good hardware/mechanics shop) to undo the BB.

I bought a quality 32mm spanner for £4.20 from a regular shop.