hss drills,detail as following:
size:0.1mm till 25mm by 0.1mm step
material: M35,M2,W9,W4,and 4241#,
surface finish:bright,titanium coated,black&bright finish,amber,amber&black,amber&bright.
manufacture process: fully ground,half ground,roll forged,milled
point angle: 135,118,130,multifork,
shank: straight shank,reduce shank,tri-flat shank，
din338 is the regular standard of hss drill bits, and different market likes different
color,about the point angle,multifork point can increase drill's quality too much ,
and tri-flat shank make drills can be gripped more strongly,avoid smooth.