Abstract: In this paper,calculation of the peg-in-hole inserting force of a flexible wrist isanalyzed in vector form.It is shown that there is a good agreement between theore-tical and experimental results.The phenomena "Block " and "Wedge ",that ought tobe considered in the part-mating procedure is discussed.Lastly,the conditions thatmust be ensured for easy carrying on of inserting operations are also given.