How to solve the problem of tap breakage during the use of a radial drilling machine?

During the operation of the swing-arm drilling machine, the breakage of the tap often occurs suddenly under great force, causing the cutting edge of the half tap broken in the screw hole to be tightly wedged in the metal. Generally, it is difficult to separate the cutting edge of the tap from the metal. To make the tap loosen in the screw hole, the vibration method can be used. When vibrating, use a sharp chisel to press against the chip groove of the tap, and gently tap repeatedly with a hand hammer in the direction of the thread until the tap becomes loose.

1. When the broken part of the tap is inside the hole, two nuts can be screwed on a broken tap with a square tenon. Insert a steel wire (the number of wires is the same as the number of tap slots) into the empty slots between the broken tap and the nuts. Then, use a hinge to pull the square tenon according to the exit target to remove the broken tap. If it still cannot be removed, the tap can be annealed with an acetylene flame or a blowtorch, and then drilled with a drill bit. At this time, the diameter of the drill bit should be smaller than the diameter of the bottom hole, and the drilling should also aim at the center to prevent the thread from being damaged. After the hole is drilled, drive in a flat or square punch and then use a wrench to unscrew the tap.

2. When the broken machine tap is only 2 to 3mm exposed above the workpiece surface, use a flat steel piece 2 to 3mm thick and 150 to 200mm long. Drill a hole at half of its length (the diameter of the hole is the outer diameter of the tap), then place the flat steel over the broken tap, leaving a gap of 0.5 to 1mm between the flat steel and the end face of the shaft. Use an electric welder to smoothly weld the broken tap to the flat steel on the same line. When welding, start from the center of the tap and gradually weld it to the flat steel on the same line. After the broken tap cools down naturally, inject engine oil into the chip removal groove of the broken tap. Gently move the flat steel left and right to loosen the broken tap, and it can be easily removed from the shaft. Hexagonal nuts with an inner diameter slightly larger than that of the tap can also be used for welding.

3. When the broken tap is exposed on the working surface for a long time, it can be unscrewed with pliers. In the manufacturing industry, tapping on shaft ends is often encountered because most of these shaft parts have undergone quenching and tempering treatment, featuring high toughness and strength, which brings a lot of difficulty to tapping and frequently leads to the breakage of pneumatic taps. Often, workpieces are scrapped due to improper handling.