10mm x 1.0 Fine thread, male, fully threaded, steel nut, 16mm long overall.
SAE flare (45 degree/inverted/double)
This is the standard Asian style nut used with 3/16"/4.75mm (CNF-3) SAE flared tubing, though the European style nuts are now being found.
The 10mm x 1.0 nut is a bit larger and has a finer thread than the 3/8” x 24 unf American nut.
Used with UM16-3 union.
Use with 3/16"/4.75mm (CNF-3) brake tubing
Caution, the 10mm nut will start in a 3/8” x 24 unf hole but will strip the threads as you tighten it.