Cutting taps
(1) tap selection guide
The cutting tap is the most common tool for machining cylindrical and conical internal threads. Since the tap is usually threaded in the drilled hole, the cutting conditions are not ideal. Chip discharge is the first problem to be faced, how to cut well in a very narrow space and well control the chip , The user is first required to select the appropriate cutting tap for the cutting performance of the material being cut.
If you know the material of the workpiece to be processed, through the color ring cone selection guide, the user only need to answer the following four questions can quickly and accurately select the most suitable tap:
Is the machined hole type a through hole or a blind hole?
The standard thread required - metric, American or imperial
Machined thread tolerance levels are 6H, 6G or other?
What type of taps do users need - DIP 371, DIN376 or other?
(2) the choice of cutting cone type
When the internal thread is tapped, all the cutting processes are done by the cutting teeth of the cutting cone part. Therefore, care must be taken to select the most suitable cutting cone type in order to obtain the best tap life and internal thread quality. In general, the type and length of the cutting cone depends on the type of thread hole, usually in the tapping hole when no problem, but the blind hole, it will produce chip problems, then need to go with the opposite Directional chip removal.
The length of the cutting cone is determined by a number of related factors, the principle of selection is to avoid the tap load is too large, too early blunt and thread size is too large. Cutting cone part should try to keep less teeth cutting teeth, or too long cutting cone will increase the tapping torque, so that the taps have the risk of fracture. C-collar company recommended to the user by the practical application of the production proved good results of the five kinds of cutting cone: Type A: long cutting cone, about 6 teeth, for processing short hole; Type B: medium cutting cone, about 4 teeth, Type C: Short cutting cone, approx. 2 teeth, suitable for processing blind holes and general aluminum, gray cast iron and copper; Type D: Medium cutting cone, suitable for all kinds of through holes and deep tapping holes; About 5 teeth, suitable for processing through-hole and can be fully broken the blind hole; Type E: ultra-short cutting cone Hanyang technology, about 1.5 teeth, for processing can be fully broken the blind hole (should be avoided). Among them, with a blade angle of the B-type tap, the chip can be removed to the direction of processing, the chip does not affect the surface quality of the thread has been processed, it is most suitable for through-hole tapping.
(3) the role of the groove
Normally, the geometry of the tap (such as the type, the number of flutes and the helix direction, cutting angle, etc.) is mainly based on the material and the use of the workpiece. In principle, for the attack ISO metric thread tap or general engineering M16 within the taps with 3 slot design, more than M16 is used 4 or more.
A tap with a left-handed helical groove allows the chip to be removed from the feed direction, making it ideal for through-hole tapping. For blind hole tapping, it is advisable to use a right-hand groove or a containment taps with a shorter cutting cone length so that the chips are discharged upward without accumulation at the bottom of the hole, while the design of the chopper can prevent the tap from moving back Was blocked by chips.
(4) surface treatment
Surface steam treatment, nitriding and TiN, FIRE, TiAlN, TiCN and MolyGlidet seven kinds of surface treatment and coating form of tap, to meet the needs of users in many ways.
Squeeze taps
The squeeze tap is a non-chip-type, cold-squeezed internal thread that requires at least a 10% ductility for the workpiece material to be machined. Similar to the rolling of the external thread, the material is squeezed by the taper of the thread to the surrounding, but does not destroy the crystalline fibers of the material. Cobalt's extruded tap has the following advantages: the use of high-strength design to reduce the risk of taps fracture; wide range of applications, the same extrusion tap can be used for both through-hole processing and blind hole processing; no chip formation, There is no problem of chip removal; high precision machining; the quality of the machined thread is good; the height of the thread to be machined is high; the tap life is high; the high speed forming and cutting speed is about 2 times higher than that of the cutting tap.
3. Thread cutter
Threaded milling cutter can achieve its superiority when processing large thread and high hardness and high strength workpiece material (of course, the prerequisite is a high-power programming and high-power driven three-axis CNC machine tools). Now, with more and more of the above functions of the popularity of CNC machine tools, thread cutter more advantages are gradually being recognized. Cobalt collar thread cutter has the following advantages:
Can effectively control the size and accuracy of the thread to be processed;
The dimensional accuracy of the orifice to the bottom of the hole is the same;
Cutting speed and feed rate can be adjusted according to different processed materials;
Can reduce the production workshop thread cutter inventory varieties, quantity and warehouse space:
The same tool can be used to process the same pitch and different diameter of the thread;
The same tool can be processed with different thread tolerance grade thread;
The same tool can be used to process left and right thread, blind hole and through hole;
Thread processing without changing the direction of rotation of the machine tool spindle;
The surface quality of the thread is very high, there is no residual chip in the root of the thread;
High processing reliability, even if the tool is damaged may not lead to scrap of the workpiece;
A high cutting speed and feed rate can be used to shorten the machining time.
4. die
Cylindrical companies produce circular die series of tools can be used for processing metric, inch, American and American pipe thread. Among them, with a screw into the groove and grinding the processing of the die can effectively improve its bite into the performance, reduce the friction when the thread processing, improve the quality of the thread surface processing.
5. tapping chuck
Floating tapping chuck: tapping range M3 ~ M20, with internal cooling and no internal cooling of two; can effectively compensate for the spindle feed and tap pitch between the difference.
Synchronous tapping chuck: tapping range M3.5 ~ M28, with a very small amount of compensation function, can greatly improve the quality of tapping and tap life.
