A aluminum bottles neck finish holds the cap, stopper, or closure with protruding threads. A bottle and its corresponding cap must have matching finishes. For example, a 24/410 bottle will only accept a 24/410 closure.
Screw thread or continuous thread closure sizes are expressed with two numbers separated by a hyphen or slash. The first number refers to the millimeter diameter measured across the inside of the cap’s opening or the outside of the bottle’s threads. The second number refers to the thread style, “GPI” or “SPI” finish. The Glass Packaging Institute (GPI) and Society of the Plastics Industry (SPI) are responsible for establishing uniform standards for glass and plastic container neck finishes. The closure industry does not necessarily adhere to the same standards, so we recommend you buy aluminum bottle and cap form us.We can ensure the tightness.