At amateur designing the need to cut external or internal thread on any part arises time. That quickly and qualitatively to perform this operation, it is necessary to know the basic rules of its performance.
It is required to you
- - part;
- - bar;
- - tap wrench;
- - lubricating oil.
Instruction
1. The internal thread is cut by the tap, external – bar. As a rule, there is more often need to cut external thread. For this purpose you need rod on which you will cut thread, bar and tap wrench for it.
2. Remember that diameter of bar has to be equal to diameter of future thread. Reliably record part in vice, it is desirable vertically. Insert the necessary bar into tap wrench and fix it. Now apply bar to the end of bar, watching that there were no distortions, it is very important.
3. The right hand thread is cut by rotation of tap wrench clockwise, left – against hour (for such thread there has to be also the corresponding bar). The bar should be rotated exactly, without breakthroughs. Surely oil its working surface lubricating.
4. At thread cutting, shaving is formed, it needs to be deleted regularly, slightly turning bar in the opposite direction. As a rule, after the bar cut several threads, further work already goes rather simply.
5. If there is no tap wrench for bar, it is possible to clamp it normal gas pipe wrench. But in this case it is much more difficult to begin threading without distortions therefore observe the exact provision of bar, do not allow key inclinations. The slightest distortion can spoil all work.
6. How to be if diameter of preparation is more than necessary size of thread? In this case the bar needs to be ground on turning lathe to the required diameter. If it is impossible to clamp part in turning lathe, it is possible to grind it on the normal electric grinder, but this work demands big accuracy. Control caliper diameter of bar, you watch that it was strictly cylindrical. Reliability of future thread depends on quality of processing of preparation.
7. Sometimes it is impossible to begin from the first the correct cutting, the thread turns out warped. In this case remove bar and tap already cut site of thread the hammer, then again repeat cutting. As the beginning of thread usually is not its loaded working site, it is quite admissible.