Materials of the Non-magnetic drill collars are from chrome manganese, low carbon alloy obtained by combining a proprietary chemical analysis and a rotary hammer process. The material is resistant to stress corrosion cracking, with high machine ability and no tendency to galling.

magnetic permeability (when MPS=1 105/4Nm)
relative max:1.010 average: Ur >=1.005

magnetic field gradient (hot spots)
max: B 0.05micro tesla/100mm

The non-magnetic drill collars exhibit the mechanical properties indicated below along their entire length. The table is derived from test samples of steel taken from a point 1± below the surface.