retainer 14 however has only a single annular groove 18 which is adapted to house sealing member 16 in this embodiment the annular groove 18 is v shaped and receives a square shaped compressible sealing member 16 preferably the square shaped sealing member 16 has semi circular extensions projecting from each corner to ensure an adequate fit in groove 18 fig4 a 4b and 5 a 5 b show chucks 10 having an engagement ring 48 attached circumferentially to the bottom outer periphery of the supporting body 12 the engagement ring 48 extends radially outwardly from the supporting body 12 creating a stepped relationship between the supporting body 12 and engagement ring 48 and forming engagement member 20 the retainer 14 has a lower portion 42 with a u shaped recess 22 formed therein the u shaped recess 22 receives the engagement member 20 the lower portion 42 of the retainer 14 has an extension 49 that wraps around the engagement member 20 to form a mechanical snap connection between the retainer 14 and the engagement ring 46 of the supporting body 12 in fig4 a 4b the retainer 14 has a two step annular groove 18 which receives a sealing member 16 having a top part with one width for insertion into one step of the annular groove 18 and a bottom part with a second width for insertion into the second step of the annular groove 18 in fig5 a 5b the retainer 14 has a single v shaped annular groove 18 for housing the sealing member 16 which in this embodiment is a compressible o ring fig6 a 6b illustrate another preferred embodiment of a chuck 10.