OK - thanks everyone for taking the time to comment - I am not clever enough to understand how to write one mail encompassing copies of multiple comments from various members so....
Regarding how the brake pipe is cut and dressed I have tried everything I can think of ie:-
1. Cut with pipe cutter and internally deburred with a deburring tool.
2. Cut with pipe cutter and then removed internal burr with 3mm drill bit.
3. Cut with angle grinder, dressed square on fine stone bench grinding wheel, added external chamfer, deburred with wire wheel.
4. Cut with pipe cutter and do nothing with the finished cut face.
All of the above made no difference.
Lubrication - I have tried the suppled die grease, engine oil, gearbox oil - no difference.
Quality of pipe - I have 3 rolls of brake pipe from differing sources - tried all - no difference.
Speed of forming - I have tried winding in the die slowly and quickly - no difference.
I was very interested in a comment made of the die transmitting a turning moment to the pipe whilst forming the flare, this causing the effect I am experiencing. This to me is highly plausible. When you look at the +£150 tools for creating brake pipe flares, the clamping arrangement of the pipe is more or less identical BUT the die is pressed into the pipe, there is no turning moment exerted.
Many people have used these tools with zero problem so I believe my problem is in the tool and the machined tolerances; I cannot remember for the life of me where I bought it from. There is no manufacturers or suppliers name on the instruction sheet so maybe its a poor copy.
I am now going into the workshop to collect the tool, put it in the box it came in, and hurl it as far as I can over the rear fence. It won't result in me producing brake pipe flares but I guarantee it will make me feel better.
My next post on the subject will be how far it went......
Thankyou all for your thoughts, comments and taking the time to post. :thumbup: