How To Use A Tap And Die Set?

  You use "dies" to cut or repair threads on bolts or pieces of metal. The metal strength of these threading tools​ exceeds the strength of most sheet metal. With the right amount of oil and care, you can cut or repair the threads of machined screws and bolts quickly and consistently. 

Finding the Right TPI

Before you can begin threading, you must first determine the threads per inch (TPI). You'll need it to grab the correct tap and/or die for the bolt, nut or hole. Most tap and die systems include some sort of gauge. They use many different "inserts" to help you match the bolt or nut to the correct TPI. some look a bit like small folding knives. There are many of these thread checkers on the market and you can find one that works for you.

Sharp Tail Screw Die

Select the appropriate tap or die

Once you have determined the TPI of the bolt, you can select the corresponding die. Keep in mind that these sets are available in both metric and SAE. manufacturers also have very small and very extensive kits. Both taps and dies have tapered threads.

 

This helps them to easily enter the bolt or nut and gently re-engrave the threads as expected. Most dies are mounted in a special wrench that holds them in place quickly. This gives you the leverage you need to turn it and guide it in its cutting path.

What about combination drilling and tapping bits?

You may have seen some of the new drill and tap bits. These go into impact drivers or drills that allow you to drill and tap in one step. It's strange how they work when you need to be very careful when tapping holes manually.

 

But they do.

These can provide super fast drilling if you stick to the recommended materials and lubricate the drill bit during use. We've tried them in a variety of sheet metal and steel. Lining up your holes and keeping them straight and level is the biggest challenge with these drills.

 

Fixing and repairing threads in bolts

Fixing threads to cross-threaded bolts using a die takes only a few steps.

Fixing the bolt in a vise

Drywall Tapping Screw Dies

First use a vise to hold the bolt in place. Since you do not want to damage the threads further, we recommend clamping only the head of the hexagonal bolt. However, if you need to clamp the shaft of the bolt, try one of the following methods to protect the bolt threads.

 

Use a few pieces of wood

Find some rubber (such as a bicycle inner tube) and place it in the jaws of a vise

Use two pieces of leather.

Align the die and start (re)cutting the threads

Once you have the bolt in place, carefully align the die so you are not tilting the bolt downward, but straight down.

Self Drilling Screw Dies

As you begin to re-torque the bolt, it may begin to warm up. This is unavoidable when rubbing two metals closely together. This will be more noticeable when you use longer thread lengths. We recommend lubricating the die with a small amount of cutting oil and keeping it cool during use. Most taps and die wrenches have an open top. Take advantage of this to add lubricant without removing the die. This also extends the life of the tap and die.

 

As you screw the die down onto the bolt, you will feel it start to catch quickly. Every few turns, you may need to back the die off a bit to clear the threads and make a better cut. This is to be expected and is similar to drilling into wood with a large drill bit. Once the die is far enough down that the bolt goes through the top, you'll know you're done.

Re-machining the hole and nut with a tap and die

Screwing (or re-screwing) the nut in using a tap is equally simple. Start by securing the nut in a vise.

Use a gauge to find the right size tap

If you do not have a matching bolt, use a gauge to select the correct size for the nut or hole you are screwing into. For those of you who make your own nuts, you may want to use an actual matching bolt to set the size. This keeps you from trying to force a gauge into a worn bolt. Depending on where it is located, this may not even be possible.

 

If you encounter a completely damaged thread, don't panic. You can always drill out the hole and re-tap it to get a slightly larger bolt. You can even fill it and re-tap it.

Secure the tap and start threading

First, place the tap into the provided wrench and secure it. Next, place the tap into the nut and begin to turn it down by hand, being careful to get it perfectly straight into the hole. As with using the mold, adding oil is a must. Pour the tap out frequently to remove any debris that has accumulated in the threads.

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