Grinding method of twist drill bit

The drill bit is a tool that relies on rotation for cutting. Generally speaking, the material is carbon steel. It is also used in many lathes, but few people know how to grind fried dough twist bits quickly and wearproof. FEWELL will introduce the grinding method of fried dough twist bits in detail：

1. The blade shall be square with the grinding wheel.
Before cutting the fried dough twist drill, the surface of the key knife and grinding wheel of the fried dough twist drill should be placed on the horizontal surface, which is the first step from the drill to the wheel.
2. The center line of the fried dough twist drill must deviate from the wheel surface by 60 degrees.
This angle is the angle of the fried dough twist drill. If the angle is different at this time, the size of the upper angle of the drill, the appearance of the main edge.The angle of the transverse blade. Here is the position relationship between the core line of the drill bit and the wheel surface, taking 60, which is generally more accurate.
Before cutting fried dough twist drill, relative leveling position and viewing angle position.
3. Grind the back from the edge.
After the blade contacts the grinding wheel, it must be grinded from the main blade to the rear blade, that is, from the blade of the drill to the grinding wheel, and then along the whole
Slowly grind the rear blade. The fried dough twist drill can be selected. Gently touch the sand wheel blade, carry out small cutting, and pay attention to the uniformity of sparks
Weigh, adjust the hand pressure immediately, and also pay attention to the refrigeration of the fried dough twist drill, which is not easy to cause injury, causing discoloration of the edge, and then quenching.
When the edge temperature is high, the drill should be cooled in time.
4. The edge of the drill should swing up and down, and the tail of the drill should not be raised.
This is a standard bit grinding function. It is mainly used to swing the bit up and down on the grinding wheel, that is, hold the bit in front of the hand to make the bit
The grinding wheel swings evenly. However, the hand of the handle cannot swing, and the back handle should also be prevented from rising, that is, the end of the drill bit cannot be raised to
Above the horizontal centerline of the grinding wheel, otherwise the blade will be passivated and cannot be cut. This is the most important step,
It has a lot to do with it. When you are grinding, start from the edge and gently rub the back corner to make it clean.
5. Ensure that the tool tip is aligned with the axis, and slowly repair the symmetry on both sides.
When one side of the drill is completed, the other side of the drill must be machined and both sides must be symmetrical. Experienced master will be in the light
See the symmetry of the drill bit in the line and grind it slowly. The back angle of the drill bit is generally 1014. The back angle is too thin and the edge of the drill bit is too thin.
Large vibration, triangular or pentagonal hole, cutting fiber shape, small back angle, large axial force of drill bit, difficult drilling, cutting speedSpeed up, the bit is seriously hot, and the bit cannot be drilled. The back angle is suitable for grinding, with center to center, symmetrical double edges and light drill clearance.
Without vibration, the aperture will not expand.
6. After double-edge grinding, the drill bit with larger diameter should be carefully ground.
After double-edge grinding, the double-edge blade tip will have a plane, which affects the center position of the drill bit, and it is necessary to twist the corner behind the blade.
The plane of the tool tip shall be as small as possible. This method is to erect the drill bit, point at the angle of the wheel, at the root of the blade, and
A small groove is injected into the tip. This is also an important point of drill center and fast cutting. Note that the grinding angle should not be worn on the main blade, which will make the front angle of the main blade larger and directly affect the drilling.