Remove Dust, Rust, and Remaining Thread Lock from the Threads with a Tap or Die Before Assembly!

When attaching and detaching bolts and nuts, if they are installed with dust or dirt on the respective threads, the correct tightening torque may not be obtained or the threads may be damaged. In such cases, we want to utilize a tap & die set. Although it is often thought that you will never need to use them unless you are making parts yourself, you should have a set of these tools because they make it easy to correct and modify threads.

A die that removes debris from male threads as well as a tap that corrects female threads should be utilized.

There are many bolts that have rusted only at the threaded part due to moisture penetration, while the head part to which the tool is applied is completely rust-free. For example, in crankcase covers and oil filter covers, if there is no female thread on the cover side (i.e., no through-hole), moisture can easily enter. Of course, even if the male and female threads are engaged all the way around, the threads can still rust.

M5, M6, M8, and M10 sizes are frequently used, so it is more convenient to have a set than to buy each size separately..5, but pitch 1 on the bike..Since 25 fine grits may be used, it is advisable to purchase a set product that includes both coarse and fine grits, or to have fine grits available separately.

When using a die to modify the male threads of a bolt, the die is set in the die holder with the side with the size stamped on it facing the bolt side. This die is M6 size with a pitch of 1. Size 0.

When attaching and detaching bolt nuts on out-of-print, old, or newer bikes that have been exposed to rain, it is nerve-wracking to worry about the condition of the threads. You will be lucky if they loosen easily, but it is not uncommon to find that they are sticking due to moisture in the gap between the male and female threads, or that the threads have been crushed due to someone forcibly tightening them in the past.

It is important to observe the condition of the threads of bolts and nuts that are somehow removed by various means, such as spraying with lubricating spray, tapping with a shock driver, or heating with a heat gun. If the threads of a rusted bolt are filled with rust, or if part of the threads of a bolt that has been removed are crushed or part of the female thread has come out like a coil, it is necessary to replace the bolt or repair the female thread by recoiling.

In addition, when the threads are not so dirty that they need to be replaced, clean the threads with a tap or die. Taps are cutting tools that make female threads and dies are cutting tools that make male threads, but they are also useful for correcting and cleaning threads that already exist. A bolt with rust or adherence on the threads can be threaded through a die to clean out contaminants all the way to the bottom of the thread valley. This is also useful for cleaning brake rotor bolts that have been coated with thread lock.

Similarly, female threads on wheel hubs where rusted bolts have been tightened on nuts or brake rotors held in place by thread lock can be cleaned by inserting a tap. Bolts with exposed threads can be cleaned with a wire brush, but a brush cannot reach inside the female threads, so a tap is best used to clean the bolt's counterpart.

Some people may think that even if a bolt or nut is a little reluctant when screwed in, it will be okay if it is tightened strongly with a spectacle wrench or socket wrench. However, if a bolt is tightened with a damaged female screw, it may lock up and stop turning even though it has not been tightened all the way to the end. The worst-case scenario can happen when a preset-type torque wrench reaches the set torque and clicks, but there is still a gap between the bolt and the part. ...... If you ignore this and tighten the bolt even harder, the situation can go from bad to worse, with the bolt breaking or the female threads coming up.

To prevent this from happening, it is a good practice to clean rusted or threadlocked bolts, as well as bolts and nuts that have come off under normal torque, with parts cleaner and run taps and dies through them before installation.

Make a habit of correcting the screw with a tap or die if it is reluctant to move near the entrance.

Aligning the bolt threads with the blade of the die and tightening clockwise removes dirt, rust, and thread lock debris from the threads. Even if the tip of the bolt is crushed, it may be corrected by passing the bolt through the die.

Without a die, a wire brush is used, but it is less efficient than a die. In particular, thread lock stuck in the valley of a screw is no match for the vigor of a die, which digs with its sharp blade. Surface dirt can be removed with a brush, but rusted bolts must be cleaned with a die when they are reused.

After cleaning the bolts with a die, the female threads should also be cleaned with a tap. With foreign matter adhering to the threads, the tightening torque will not be stable, which may cause malfunctions or problems.

When installing any kind of screw, from small screws and bolts to spark plugs, the first principle is to turn it with the fingertips. The biggest cause of damage when installing bolts and screws is mismatch between the male and female threads. If you try to tighten a screw by hand with the male screw tilted against the female screw, you will notice a discomfort after only half a turn or so.

However, if a screwdriver or socket wrench is used from the start, it may be tightened even if it feels a little stuck. This is even more so with fine threads. In the case of engines where bolts are installed or spark plug holes are deep, it is not uncommon to have to rely on tools because your fingers cannot reach them. Even in such cases, however, thread galling can be detected early by turning the bolt with the shaft of the extension bar to prevent the tightening torque from increasing.

If you feel discomfort in the early stages of tightening due to the inclination of the screw or bolt, as well as rust on the threads or residual thread lock debris, be sure to remove it once, without forcing it to proceed to correct the threads with a tap or die. Although it may seem tedious, there are many instances where work that seems like a detour becomes a shortcut.