four numbers.
It depends on what material and how many there are in the bundle.
8.8 is a quality measurement, 20 mm is a size measurement. They're not dependent on each other. You can have a 20 mm bar in any quality, as you can have an 8.8 quality bar in any size.
20 mm
It would take 20 pieces of 3 mm thick paper to make a stack that is 6 cm thick. This is because 1 cm is equal to 10 mm, so each piece of paper adds 3 mm to the height of the stack.
20 mm should still be 20 mm!
None but 20 mm = 2 cm
All U.S. bills are approximately 0.11 mm thick. I.e. a stack of 9 of them is about 1 mm high. In inches, a single bill is about 0.0043 inches thick. A standard bundle of 50 bills ($50 to $5000) is about 5.5. mm high (0.215 in at 233 to the inch).
20 mm - 0.2mm = 19.8
10m (10,000 mm) of water column is about 0.98 bar (P=density*specific gravity*height=1000*9.8*10) 5000 mm WC is 0.49 bar then.
20 mm cannons.
Circumference = 20*pi mm
0.001. because a micron is 1000 times smaller than a millimetre