Machining of grooves

Recommendations for the calculation and machining of piston grooves for hydraulic applications.
Diameter from 18 to 200 mm, all rings except those on which the surfaces are not parallel.

In case of bilateral thrust, both groove surfaces will require precision grinding: Ra ≤ 0.8nm

Cylinder bore..........................D = d1, tolerance H7 (d1: nominal ring Ø)
Piston diameter .....................d = d1, tolerance f8
Groove base gap.....................z : according to d1, see chart P1
Groove base diameter............dL = d min - (2.a1 max + z)
Tolerance on dL.....................-0.00 / -0.20 mm
Groove width..........................L = h1, tolerance, see chart P
Groove base radius.................R : according to dl, see chart PI