Angrybear is 100% correct of course.

It does not blow out because - it's 850 p.s.i.

PSI = Pounds per SQUARE INCH.

Geddit?

If for the sake of simplicity the piercable area were square, 1/16th of an inch square, then the area would be 1/16th x 1/16th of an inch square (0.00390625 of an inch) thus the actual force on the piercable area (the number that came before, multiplied by 850) would be 3.32 lbs... not a lot I don't think.