Container and/or closure therefor

The combination of a container and a cap comprising:

• a container having a solid wall with wall portions defining an opening wherein an enclosure is defined capable of containing fluids;
• a cap adapted to close said opening;
• said container having a first surface and a second surface and said cap having a third surface, a fourth surface, and a fifth surface;
• said third surface and said fifth surface defining a circular edge;
• said first surface cooperating with said third surface and said fifth surface wherein said first surface and said circular edge engage each other in a closed line when said cap is fully inserted;
• said second surface and said fourth surface engaging each other to form a stop against further movement of said cap and container toward each other;
• said circular edge being part of a solid cylinder integrally connected to and extending downwardly from said cap and said first surface being flat and positioned to engage said circular edge of said part of said solid cylinder, wherein the closed line has a width perpendicular to its length within a range of 0.5 millimeters to 1.5 millimeters;
• and
• means for forcing said cooperating surfaces together with a pressure of at least 100 psi;
• said first and third cooperating surfaces meeting at a first angle of between 75 degrees and 105 degrees and said first and fifth surfaces meeting at a second angle of between 75 degrees and 105 degrees.