For collecting undisturbed samples of 38 mm dia for Triaxial Shear strength and Unconfined Compressive strength either straight from the field or from a sample of larger diameter. The wall thickness is maintained approximately 1. 6 mm with an area ratio approximately 17 per cent. Both relieved and unrelieved sampling tubes are available. In the relieved type of tube, the internal diameter is relieved by about 0. 5 mm (inside clearance 2%) beyond approx. 19 mm length from the cutting edge of the tube. This is most suitable for highly cohesive soils. In the unrelieved type, the internal diameter is uniform through out. This type is most suitable for soils of low cohesion. These 38 mm dia tubes are available in different lengths.
Salient Features

• Unrelieved : (a) 150 mm (b) 200 mm (c) 225 mm (d) 300 mm long.
  
  Relieved
  
• : (a) 150 mm (b) 200 mm (c) 225 mm (d) 300 mm long.