Park Tool CNW-2 chainring nut wrench review

I purchased this to hold the nut on the rear derailleur hanger.  After trying to hold it with two flat bade screwdrivers, I decided to buy the right tool for the job.  I went for the Park one as they have such a good reputation and at only £3.99 from Chain Reaction Cycles it was a small price to pay.

The tool is a bit of a lightweight and I'm not impressed with it.  For only £3.99, I suppose you can't expect much, but it could have been far better.  It is about 11cm long and made from 1mm thick pressed steel with a bright chrome finish.

The problem I found is that it is too thin and therefore much thinner than the size of the slot in the nuts and means you can't put much force on it before it pops out.  Being such a smooth glossy finish probably doesn't help either.  Also the ends (the vital bits that fit in the slot of the nut) have slightly rounded sides which also doesn't help it stay in place under force.  I'm going to get a metal file to it to see if I can make the ends completely flat to see if that improves it.  But ideally it should be made out of a metal that is two or three times thicker.

My rating: 4/10


Does anyone know of any other similar tools for holding the slotted nuts?
CRC sell the BBB BoldGrip BTL32L wrench, but it looks to be no better than the Park one.  See http://www.chainreactioncycles.com/Models.aspx?ModelID=60760