The enlarging ring serves as a friction reducer between the rods and the ground and is used in static tests (CPT, CPTu, and S-CPTu). Increasing the diameter of the hole facilitates its penetration.
| Type | Outer diameter | Use |
| Fixed | ∅ 40 mm | Already mounted on the rods |
| Floating | ∅ 50 mm | To be inserted between two rods with a fixed enlarger |
It is essential, when choosing to use the enlarging ring, whether you decide to use the fixed or floating type, to start from the first rod closest to the tip, in order to progressively reduce friction from the very beginning of the test.
The enlargers produced by Pagani undergo specific treatments to ensure wear resistance.