14 thereby eliminating the primary cause of failure of most prior art teeth that is most teeth in the prior art are attached to the outside of cap 12 and thereby are exposed to severe pressure and shear forces that cause the tooth to pry away from an ordinary cap in this instance similar to teeth in a human being the digging tooth 14 is securely inserted in female socket 26 and surrounded by conforming cylindrically shaped chamber 28 outer race channel 30 enables ball bearings and inner race means 32 on digging tooth 14 to secure digging tooth 14 in socket 26 additionally because of inner race means 32 being constructed with ball bearings or the like digging tooth 14 is allowed to revolve within cylindrically shaped chamber 28 this enables digging tooth 14 to rotate perpendicularly to the motion of the excavating bucket as a result much of the shear forces applied to the digging teeth are reduced additionally as a result of the rotation of digging tooth 14 within female socket 26 digging tooth 14 is constantly wearing on different portions of the hard outer shell 36 this in turn results in a constant 34 self sharpening 34 of digging tooth 14 because digging tooth 14 has a harder inner core 38 the constant.