Fastener holder for power tool

A fastener holder comprising:

• a driving tool stem including a shaft extended therefrom for engaging into with a power tool and for being driven by the power tool, and including a bore formed therein, and including a plurality of orifices formed therein and communicating with said bore of said driving tool stem, and including an aperture formed therein and communicating with said bore of said driving tool stem,
• a driving tool shank rotatably engaged in said bore of said driving tool stem, and including an outer peripheral groove formed in said driving tool shank, and including a compartment formed in said driving tool shank and having a non-circular cross section for engaging with a tool element and for allowing said tool element to be rotated and driven by said driving tool shank, and including a plurality of depressions formed in said driving tool shank,
• an anchoring member slidably engaged in said aperture of said driving tool stem and extendible into said bore of said driving tool stem for engaging with said outer peripheral groove of said driving tool shank and for anchoring said driving tool shank to said driving tool stem and for guiding and limiting said driving tool shank to rotate relative to said driving tool stem,
• a plurality of bearing members slidably engaged in said orifices of said driving tool stem respectively and extendible into said bore of said driving tool stem for selectively engaging with said depressions of said driving tool shank and for selectively anchoring said driving tool shank to said driving tool stem and for allowing said driving shank and said tool element to be selectively rotated and driven by said driving tool stem, and
• a barrel including a first segment having a relatively greater chamber formed therein, and a second segment having a relatively smaller space formed therein and having an inner diameter smaller than that of said chamber of said barrel for slidably receiving and engaging with said driving tool stem and for forming an engaging surface between said chamber and said space of said barrel, said second segment of relatively smaller of said barrel being selectively engageable with said bearing members to force said bearing members to engage into said depressions of said driving tool shank respectively and to anchor and lock said driving shank to said driving tool stem and for allowing said driving shank and said tool element to be selectively rotated and driven by said driving tool stem, and said bearing members being disengaged from said depressions of said driving tool shank to unlock and release said driving shank from said driving tool stem when said bearing members are moved out and disengaged from said relatively smaller space of said barrel and engaged in said relatively greater chamber of said barrel for allowing said driving shank to freely rotate relative to said driving tool stem and for preventing said driving shank from being rotated and driven by said driving tool stem.