Firstly,
Thankyou to all the guys that have responded to my post with a constructive reply.
The reason I started this thread is due to the fact I am in the process of designing and manufacturing a tool to aid in the removal of A/C rivets to improve the process. I have carried out this task frequently and thought of an idea to make the process more accurate and more efficient. I therefore canvassed for current practices used by the professionals that use this forum (excluding "itsallbollox")
Just to finish, "itsallbollox" (apt name) if you have nothing constructive to add to this thread kindly go elswhere and annoy someone else with your pointless boring posts that are about as intelligent as your screen name.....