The Use of Tapping Wrench and Precautions
This article will introduce you about the use of tapping wrenches and precautions.
1、Align the tap with the eye hole and judge it by eye so that the tap is perpendicular to the plane of the workpiece.
2、Turn the tap one turn, from the front and side, two aspects to observe, test whether the tap is right, that is, whether the tap is perpendicular to the work plane, if necessary, you can use the right angle ruler from the front and the side to test whether it is right, if it is right, then turn the tap two turns, still use the above method, test whether it is right.
3、In tapping, if you feel the effort of forward rotation, it is not forced to rotate, should immediately stop, backward a quarter of a turn to remove the cutting part of the tap and the chips accumulated around the eye, and then continue to attack forward.
4、If the tapping is not correct, the tap should be reversed and re-aligned, otherwise it will make the tapped screw hole tilt.
5、The force must be even when tapping, you can press the wrench with one hand, hold the tap with one hand and rotate with even force, or press the wrench with two balanced hands and rotate with even force.
6、The wrench used should be suitable for the size of the tap, and when it is hard to twist the wrench, you should never add a long set on the wrench.
7、After the tapping is finished and the tap is turned backwards, after loosening the tap with the wrench, the wrench should not be backed up together with the tap, which should be especially careful to prevent damage to the threads and tap in the screw hole.
8、After taking out the tap, pour out the accumulated chips in the threaded hole, or fill it with oil, pull it out with a hook, or blow it out with compressed air, but do not blow with your mouth to avoid flying chips into your eyes.
9、When tapping, encounter material with stones or tapping can not be tapped, you can first use three tapping tap in the tapped part back to reduce the cutting force, and then continue to use the head tapping tap tapping.
Machine tool taps
1、The center of the working screw hole should be in a straight line with the center of the tap.
2、When the tap into the workpiece has been drilled on the bottom hole should be held by hand to avoid collision between the tap and the workpiece.
3、Tapping on the machine, in order to avoid excessive force on the tap and break, it is best to use a protective device tapping tool.
4、The length of tapping on the machine tool or tapping tool is positioned accurately, the length of tapping can not be equal to the depth of the hole, generally should be less than the depth of the bottom hole 1 to 2 mm, sometimes a little less, the specific can be pre-drilled according to standard regulations.
5、When tapping through-hole threads on the machine, it is best to take out the tap through the workpiece and not to rotate it back to prevent possible damage to the tapped threads, and when tapping through-hole threads, make the machine spindle rotate in the opposite direction and back out the tap.
The following coolants are generally used: emulsion, mixed oil, vulcanized oil and vegetable oil. The first few coolants have higher performance but lower lubricity, among which emulsion has the highest cooling and lowest lubricity, while vegetable oil has the lowest cooling and highest lubricity. When cutting at high speed, it is better to use floating mixed oil. When tapping with taps, if the thread finish is required to be high, vegetable oil and vulcanized oil can be used in addition to reducing the cutting speed.