TOSG spiral wire-tapping: spiral flute tap chip flutes are spiral, according to the rotation were divided into left and right hand. When L-chip downward spiral flute tap-tapping row, suitable for through-hole; discharged right-handed spiral flute tap tapping up chips suitable for blind holes. Spiral wire-tapping screw can be divided into oxide wire tapping, wire-tapping screw hole special, special stainless steel spiral wire tapping, wire tapping titanium screw. EX-SUS-SFT special stainless steel spiral wire tapping.