4, bit of edge to bobbing up and down, bit the tail can’t case become warped.
This is a standard drill grinding movement, the main cutting edge on the grinding wheel is to bobbing up and down, that is evenly to drill bit at the front hand bobbing up and down on the surface of the grinding wheel. Does not swing handle of hand, but also prevent after the handle upwards, namely high bit the tail can not become warped on the center line of the grinding wheel level above, or you will make the edge grinding blunt, not cutting. This is the most crucial step, drill grinding well or badly has a lot to do with this. In the grinding, you should begin from edge angle and then back gently over the blade back more bright and clean.
5, to ensure blade axis, slowly balanced on both sides.
Side edge grinding, grinding blade on the other side again, you must ensure that the blade in the middle of the bit axis, the blade on both sides to be symmetrical. Experienced teachers will be on the light see drill point symmetry and slowly grinding. After the drill cutting edge angle is 10 ° – 14 ° commonly, after angle, the cutting edge is too thin, when drilling vibration, orifice trilateral or pentagon, chip a needle angle is small when drilling axial force is very big, it&rsquo s not easy to cut force, temperature rise, and bit fever is serious, even unable to drill. After suitable angle grinding, angle top pointed to two edges is symmetrical, drilling the drill clearance light with no vibration, aperture will expand.
6, two grinding, the larger diameter bit also notice the bit angle top pointed.
Drill two grinding, both the sharp edge will have a flat edge, the center of impact drill positioning need to pour at the back of the blade angle, the tip of the blade plane grind small as far as possible. Which method is to drill bit, aiming at the angle of the grinding wheel, pour a little to the blade groove behind the blade root,. It is also a bit centering and cutting light the important thing. Note that when grinding blade, don’t be on the ground to the main cutting edge, it will make the main cutting edge rake angle big, directly affect the drilling.
Of course, there is no certain set about grinding drill style, we need to accumulate experience in practice. We would mill drill better by comparison, observation, trial and error.

Stay tuned for detailed product information company official website: http://www.langfengmetallic.com/