An tap is an tool that is used to cut internal threads in a hole. The tool that is used to hold a tap and turning it is called a tap wrench. If the user uses the wrong size of tap wrenches, the tap may break inside of the workpiece.
If a tap breaks inside of a workpiece, it is difficult to remove the broken tap from the workpiece. To avoid breaking a tap with a workpiece, it is important to ensure that the size and type of the tap wrenches match the size of the tap being used. There are four main type of tap wrenches, each of which is used for a specific task.
How to Use Taps and Tap Wrenches
T-handle tap wrenches are used with small taps because they allow the user to utilize only one hand to performing the task. Bar adjustable tap wrenches are used with medium sized taps because they allow the user to utilize two hands to perform the task. Ratcheting tap wrenches is used in tight spaces with taps because they allow the user to turn the tap without being able to make a full rotation.
Double-end tap wrenches are used in everyday machine screw size because they have fixed jaws that hold the tap. The size of the tap that is used determines the size of the tap wrench that is required. Small sized taps, which are number 0 to a quarter inch or 6 mm in size, require small sized tap wrenches.
Medium sized taps, which range from an eighth inch to three-eighths of an inch, require medium sized tap wrenches. For taps that are large in size or extra-large in size, such as taps that are half-inch in size to 1 inch in size or 25 mm, the size of the tap wrench will also be large in size or adjustable bar tap wrenches will be used. This is due to the fact that large taps require longer handles to allow for the proper leverage to turn the tap without causing it to bind.
If the short handle of a short tap wrench are used for a large tap, the large tap may bind in the workpiece. Taps are also classified according to the way that they cut the threads in the workpiece. Taper taps has a long chamfer at the end of the tap.
This type of tap is used to start the threads in a workpiece. Plug taps have shorter leads than taper taps and are used for most through holes in a workpiece. Bottoming taps are similar to plug taps, but have very short leads; these taps are used for cutting threads in blind holes to the bottom of the blind hole.
Spiral point taps push metal chips in the workpiece in a forward direction. Spiral flute taps pull metal chips in the workpiece in an upward direction. Roll-forming taps do not produce metal chips in the workpiece because they work by simply displacing the metal at the workpiece to form the threads.
To use a tap, the individual must first use the appropriate drill bit to drill a pilot hole in the workpiece. This pilot hole will be the one that is threaded with the tap. For instance, if the screw that will be used in the workpiece is a #10-24 machine screw, a number 25 drill bit will be used to drill the pilot hole.
Additionally, metric taps require specific metric drill bits; for instance, a metric tap size of M6 will require a 5 mm drill bit, and a metric tap size of M10 will require an 8.5 mm drill bit. Using the correct drill bit will ensure that enough material will be present for the tap to create strong thread in the workpiece. To prevent the tap from breaking when cutting threads in a workpiece, there are specific procedure that the user must follow.
First, it is important to ensure that the tap is perfectly square to the workpiece. If the tap is not square to the workpiece, the tap will create crooked internal threads on the workpiece and may break the tap. Second, if the workpiece contain steel or stainless steel, cutting oil must be used to allow the tap to turn within the workpiece.
Dry tapping can be used for workpieces that contain cast iron. Third, when cutting internal threads, use a rhythmic motion to turn the tap forward, then reverse the tap half of a turn. Reversing the tap half of a turn will help to break the metal chips that is created in the workpiece.
If the metal chips are not broken, they can potentially become clogged within the tap. If the metal chips get clogged in the workpiece, the tap will bind within the workpiece; hence, the tap will break. Finally, it is important to always monitor the resistance of the tap.
By feeling the resistance of the tap, the individual can sense when the tap begins to bind and remove the chips before the tap breaks.
