PEERCHEER offers BTW NTW HTW surface set reaming shell use for use with BTW NTW HTW core barrels. BTW NTW HTW surface set reaming shell have pads of tungsten carbide ,TSD pins or diamond stones.Each pad is protected with tungsten carbide strips or TSD pins on both the leading and trailing edges to help protect gauge and improve life.TW series surface set reaming shell is available for application in standard DCDMA B N H size.