Long taper shank twist drill bits DIN341 1) DIA ... according to the national standards,including general, long, lengthened and extra-long taper shank twist drills,the products quality and ... long life-span have been keeping ahead in the tool-making industry which make them the strongest products of the company ... ,Bright,TIN coatedProcess:Roll Foreged,milled,Extruded Long taper shank twist drill bit DIN341