1) to determine the diameter of high-speed drilling of tooth bottom
High speed drilling and tapping machine taps in the tapping process, the cutting edge is the main cutting metal, but also metal extrusion effect, thus forming a metal bump and to the cusp activities of the scene, so before tapping, drilling aperture (i.e. bottom) should be larger than the inner diameter of thread. The bottom diameter of the available manual or according to the following formula accounting experience:
Brittle materials (cast iron, bronze, etc.): drilling diameter d0=d (thread diameter) -1.1p (pitch)
Plastic data (steel, copper, etc.): drilling diameter d0=d (thread diameter) -p (pitch)
2) determination of borehole depth
When we attack the blind hole (underhang hole), the depth of the hole is greater than that of the thread because the tap cannot be attacked. The depth of the blind hole can be calculated according to the following formula.
Depth of the hole = depth of the required thread
(1) taps
A high speed drill tapping machine taps is a forming tool used to process smaller diameter internal threads, usually made of alloy steel 9SiGr and made by heat treatment. Tap M6 to M24 a mortal into two branches, two, said the nose cone; M6 and M24 over a set of three branches, namely, the two and three cone cone cone. Each taps has the part and the handle of the task. The part of the task is made up of the part of the cutting and the calibration part. There are several (usually three or four) chipping grooves in the axial direction, and a few blades (cutting edges) and the front angle are formed in response. The cutting part (that is, the unfinished part of the tooth) is the main part of the cutting thread, often grinding into a cone, so that the cutting load is assigned to a few knife teeth. Cone cone angle is small, with 5 to 7 teeth; two the cone angle is bigger, with 3 to 4 teeth. The calibrated part has a perfect tooth, which is used to repair the thread and guide the taps along the axis. Handle with the head, the effect is to carry and hinge phase and transfer torque.
(2) reaming
The hinges of the high speed drilling machine are used to hold the taps, which are commonly used in adjustable hinges. The twisting handle can adjust the size of the square hole so as to hold the taps with different dimensions. Hinge length should be selected according to their size in order to control the tap, tapping the torque force due to the defect and avoid tap off.
Key points and precautions of tapping the thread
(1) on the basis of the threaded hole on the workpiece size, accurate selection of the tap, two cone cone, not inverted by.
(2) when the workpiece is clamped, it is necessary to make the middle of the hole perpendicular to the jaw, so as to avoid the twist of the thread.
(3) high speed drilling and tapping machine with taper thread is screwed into the first 1 ~ 2 times, to reflect on whether the tap and vertical hole face (which can be visual or square in two to reflect perpendicular). When the cutting part has been cut into the workpiece, it should turn 1/4 circle for every 1~2 turns, so that chip can be broken off, and no pressure can be applied again, that is to change the pressure only, so as to avoid the thread teeth of the taps collapse or the teeth are thin.