What Is a Tapper?
A tapper is a tool with a mechanism that grips and holds a tap for machining threaded holes in steel and other materials.
However, a wide range of tappers may also be referred to as tappers, including those intended to be attached to a machine tool for machining, hand drill-type tools that are turned by hand, and tools that use compressed air to rotate a tap attached to their tips. Although there are various names such as tapper and tap holder, all tappers have in common that there is an adapter to hold the tap.
How to Use Tappers
The following will explain how to use a tapper:
Fix the shank of the tap to the insertion slot of the tappers.
Common drill chuck fixing methods include keyed and unkeyed. With a keyed drill chuck, the chuck handle (chuck key) is inserted into the three side holes and rotated to open and close the chuck section. Insert the shank of the tap in the open position, and rotate the chuck handle to secure it so that it can be evenly chucked by the three jaws. With the keyless drill chuck, the chuck handle is not used, and the tap can be secured simply by rotating the ring after inserting the shank of the tap.
Once the tap is secured, lightly press the tappers so that the tip of the tap is straight at the position where the tap hole is to be drilled. Be careful not to press down more forcefully than necessary, as the screw hole may be crushed or the tap may be damaged.
How to Select Tappers
Regarding hand-held electric tappers, the following points should be taken into consideration when selecting one:
- Tapping capacity
Each tapper has a different thread hole size that can be processed. It is determined from the cutting torque and other factors assuming the machining of screw holes in carbon steel for machine structural use. Be sure to check whether the screw size you want to machine is compatible with the taper.
In the same way that taps themselves may require a change in material depending on the material to be processed, there are some models of tappers that do not recommend certain materials to be processed. If you plan to process special metals, it is recommended that you contact the manufacturer before purchasing.
- Applicable Tap Shank Dimensions
The shape of the shank part is important to fix a tap. - Rotation speed
Check the cutting conditions and make sure that the tappers have acceptable rotation speed. The rotation speed can be calculated from the cutting speed and the tap shape. Compared to this, there is a certain amount of guideline for cutting speed depending on the work material. Slower cutting speeds are required for stainless steel than for aluminum, cast iron, and plastics.
It is important to note that stainless steel, in particular, will require a slower rotational speed. Some tappers have an adjustment mechanism for rotational speed, so if you are unsure, check to see if an adjustment mechanism is available.
- Pre-hole machining or not
While machining a screw hole typically requires the preparation of a pilot hole, it’s worth noting that some tappers may not support the machining of preparation holes. If a separate drill for preparing pilot holes cannot be made, it is important to assess whether the tapper can handle the preparation of pilot holes. - Necessity of electric power
Before purchasing tappers, it is important to consider whether they need to be electrically powered. If the main purpose is to drill holes with threads up to M6 size, a tap drill set for manually drilling screw holes may be sufficient. Also, if you use it in a place where electricity is not available, of course, you cannot consider buying an electric tapper and another type would need to be considered.