Ring pull cans ?

[Creepy]

I am amazed at the accuracy of the cutting of ring pull cans - I have not come across one that was opened EG. by crushing etc. only some that the ring pulls off.(thats not what I mean) its the accuracy ot the cutting of the or thinning of the part that detaches ? Hope that makes sense !

[RATTER15]

Clear as mud!!

[heathfield]

The metal used for the lids actually tears relatively easily. If you grip a lid using two pairs of pliers placed close together, and apply a tearing action, you'll see what I mean. The leverage action on the ring-pull is about 6 to 1, and the area that the pressure is applied to is small, giving a high 'pound per square inch' point pressure. The groove is actally quite shallow, but is enough of a weakness for the lid to be punctured on the line, and for the tear to follow it For accuracies, I'm also surprised by those sachets of sauces you get. Some have a very narrow edge seam, yet they manage to cut a really teensy nick on the edge as a starting point for tearing them open.