In {TAIL ~ this annular space section}, {HEAD ~ the pin} is provided with a groove which is tapered such that the diameter of the pin increases towards its open side 
In { TAIL ~ this annular space section } , { HEAD ~ the pin } is provided with a groove which is tapered such that the diameter of the pin increases towards its open side
REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH