EN 10226 threads replace ISO 7, recognised at world level.

EN 10226 threads, with a 55° angle between the flanks and a connectable root that favours sealing

During 2004, EN 10226 threads replaced ISO 7 threads, but only by fact as a standard re-edition. The new threads are suitable for creating pressure tight joints. They can, in fact, be found in valves and unions, in particular those products that respect ISO 4144 or EN 10241.
In order to seal, the conical external EN 10226 thread connects with the mother screw, which is cylindrical. This is not enough to guarantee sealing though, so a specific sealant is used, even for high pressures.
There are specific sealants that can also be used in corrosive environments or where high temperatures are present.
The main parameters of EN 10226 threads are their shape, which is rounded at the crest and at the root, and a symmetrical crest with a 55° angle between the flanks. In addition to the shape, the standard also defines the other sizes, the tolerance limits, and also how the threads must be indicated on drawings for threaded connections from 1/16 up to and including 6.