►Changsha langfeng introduce the operation and of taper shank twist drill (1). Determining the feed rate: Feed rate is generally depend on people&rsquo s experience, the value is general 0.08-0.12mm / rotation or 0.6-1.0mm / sec, feed speed is [Read More]

(1) The diameter of  high-speed-steel twist drill twist drill can be influenced by the aperture, spiral grooves make it be more detailed core drilling, drill rigidity is lower. There are only two edge band guidelines, hole&rsquo s axis are easily [Read More]