Be careful with the nuts from B&Q. They are all metric sizes as I bought some 10mm ones and they did not fit 3/8 axles. Stick to ones from the bike shops!
Also be careful with skyway axles as the majority of them have threads with a different number of threads per inch (I think standard is 24 tpi but skyways are 26 tpi or vice versa I can never remember which way round!)