DIN 3863 is Compression couplings - Spherical liners - Design and type of port end U and Y
It is often used in hydraulic hose fittings with metric female multiseal.
Both male and female have straight metric threads. Use a 30-degree gauge to measure
seat angle as this dimension is taken from the fitting centerline.
The male has a 60-degree seat. The female has a 24- or 60-degree seat. The seal takes
place by contact between the 60-degree seat in the male end and the respective sealing area in the female end.