The recently developed Gouda Heavy Duty (GHD) thread is the new standard screw thread for the 36 and 44 mm CPT tubes, the 56 mm casing tubes and the new generation of 10 cm² and 15 cm² piezocones. The thread has many advantages over the other threads currently available:
- Optimal balance between male and female threads
- Single-entry thread, so much less susceptible to loosening during the CPT process
- Only 3 revolutions required to close or open
- Easy to clean with a steelwire brush
- Closes superbly resulting in a very good resistance to water inflow
- Cross-over tubes are no longer
Dimensions and Characteristics
Available (effective) lengths : 1,000, 500 and 300 mm
Outer diameter : 36 mm
Inner diameter : 16 mm
Weight : 6.5 kg/m
Length of the MALE thread : 43 mm
Outer thread diameter (top) : 22 mm
Outer thread diameter (base) : 31 mm
Required number of turns to lock / unlock : 3.5
