A screw with multiple thread angles comprising: a head ; a shank extending outwards from said head ; and a main threaded portion having a plurality of thread convolutions spirally disposed on said shank , wherein each of said plurality of thread convolutions of said main threaded portion includes a root connected to said shank , an upper thread flank extending outwards from said root , a lower thread flank extending outwards from said root and connected to said upper thread flank , and a thread crest formed along a junction of said upper thread flank and said lower thread flank ; characterized in that each of said plurality of thread convolutions includes opposite first upper and lower flank sections extending from said root and respectively defined on said upper thread flank and said lower thread flank , opposite second upper and lower flank sections extending from said first upper and lower flank sections respectively, and opposite third upper and lower flank sections extending from said second upper and lower flank sections to said thread crest respectively, a first thread angle (334α) being defined between said first upper flank section and said first lower flank section and ranging from 70 degrees to 75 degrees, a second thread angle (335α) being defined between said second upper flank section and said second lower flank section and ranging from 37 degrees to 43 degrees, a third thread angle (336α) being defined between said third upper flank section and said third lower flank section and ranging from 20 degrees to 23 degrees, a plurality of notches being cut into said thread crest , each of said plurality of notches including a chip-guiding surface recessed into said thread crest , an upper cutting edge formed along a junction of said chip-guiding surface and said upper thread flank , and a lower cutting edge formed along a junction of said chip-guiding surface and said lower thread flank . a head ; a shank extending outwards from said head ; and a main threaded portion having a plurality of thread convolutions spirally disposed on said shank , wherein each of said plurality of thread convolutions of said main threaded portion includes a root connected to said shank , an upper thread flank extending outwards from said root , a lower thread flank extending outwards from said root and connected to said upper thread flank , and a thread crest formed along a junction of said upper thread flank and said lower thread flank ; characterized in that each of said plurality of thread convolutions includes opposite first upper and lower flank sections extending from said root and respectively defined on said upper thread flank and said lower thread flank , opposite second upper and lower flank sections extending from said first upper and lower flank sections respectively, and opposite third upper and lower flank sections extending from said second upper and lower flank sections to said thread crest respectively, a first thread angle (334α) being defined between said first upper flank section and said first lower flank section and ranging from 70 degrees to 75 degrees, a second thread angle (335α) being defined between said second upper flank section and said second lower flank section and ranging from 37 degrees to 43 degrees, a third thread angle (336α) being defined between said third upper flank section and said third lower flank section and ranging from 20 degrees to 23 degrees, a plurality of notches being cut into said thread crest , each of said plurality of notches including a chip-guiding surface recessed into said thread crest , an upper cutting edge formed along a junction of said chip-guiding surface and said upper thread flank , and a lower cutting edge formed along a junction of said chip-guiding surface and said lower thread flank . <EOS>