How to grind twist drill bits fast and durable

We often use twist drills in our lives, and today I will teach you how to grind twist drills quickly and durably.

1. The blade should be squared with the grinding wheel. Before the twist drill is cut, the surface of the twist drill key knife and grinding wheel should be placed on a horizontal plane. This is the first step from the drill to the wheel.

2. The centerline of the twist drill must be 60 degrees away from the wheel deck. This angle is the twist drill angle, if the angle is different at this time, it will immediately endanger the size of the upper corner of the drill bit, the appearance of the main edge, and the angle of the horizontal edge. Here is the position relationship between the core line of the drill bit and the wheel surface, take 60, this angle is generally more accurate. Before cutting the twist drill, the relative level pays the relative level position and the viewing angle position.

3. Grind your back from the edges. After the blade touches the grinding wheel, it must be ground from the main edge to the back edge, i.e. from the cutting edge of the drill bit to the grinding wheel, and then slowly grind along the entire rear edge. The twist drill can be selected, gently touch the sand wheel piece, carry out a small amount of cutting, and pay attention to the uniformity of the spark, immediately adjust the hand pressure, but also pay attention to the refrigeration of the twist drill, which is not easy to cause burns, cause discoloration of the edges, and then quenching. When the edge temperature is high, the drill bit should be cooled in time.

4. The edge of the drill bit should swing up and down, and the tail of the drill bit should not be raised. This is a standard drill bit grinding effect, mainly swinging the drill bit up and down the grinding wheel, that is, holding the drill bit in front of the hand, so that the drill bit swings evenly on the grinding wheel. However, the hand of the handle cannot swing, and it is also necessary to prevent the back shank from rising, that is, the end of the drill must not be raised above the horizontal center line of the grinding wheel, otherwise the blade will be blunted and cannot be cut. This is the most important step, and whether the bit grind is good or bad has a lot to do with it. While you're grinding, start with the edges and gently rub the back corners to make them clean.

5. After double-edged grinding, drill bits with larger diameters should be carefully ground. After double-edged grinding, the double-edged tip will have a plane, which affects the center position of the drill bit, and the corner behind the blade needs to be twisted, and the plane of the tip is as small as possible. This method is to erect the drill bit, point it at the angle of the wheel, at the root of the blade, and inject a small groove at the tip of the knife. This is also an important point for drill center and fast cutting. Note that when the grinding angle should not be worn on the main cutting edge, so that the front angle of the main cutting edge is large, which directly affects the drilling.

   
   

Precautions for using drill bits

  1. The drill bit should be packed in a special box to avoid vibration and collision.

  2. When using, the drill bit taken out of the box should be immediately loaded into the spring chuck of the spindle or the tool magazine of the automatic replacement of the drill. Then put it back in the box when you are done with it.

  3. The diameter of the drill bit should be measured using a non-contact measuring instrument such as a tool microscope to prevent the cutting edge from being scratched due to contact with the mechanical measuring instrument.

  4. Generally, the wear of the cutting edge of the drill bit can be checked with a 40x stereomicroscope.