G3/8 vs G4: specs compared

Updated 05 September 2026.

113.03 mm
G4 wins on major diameter

On major diameter, G4 leads: 113.03 mm versus 16.662 mm.

SpecG3/8G4
DesignationG3/8G4
Major diameter16.662 mm113.03 mm
Threads per inch / pitch1911
Thread formparallel, 55 degreeparallel, 55 degree
Seals onflat washer or bonded seal on the faceflat washer or bonded seal on the face

Questions and answers

Which has the higher major diameter, G3/8 or G4?

On major diameter, G4 leads: 113.03 mm versus 16.662 mm.

How do G3/8 and G4 compare?

On major diameter, G4 leads: 113.03 mm versus 16.662 mm.

Compared here