at college 2night,, the fella who looks after the stores(big tony),, showed me a different way of bending copper pipe..... for 15mm copper u measure 70mm back from the measurement given and line that up with the back of the former... he said there's a mesurment back for 135 Degrees but he couldnt remember, has any1 heard of this before and any1 know the measurment ... hope that makes sence. thanks men