LeapZipBlog: Frank Xu's blog: Metric Taps, simple but highly useful tools

Metric Taps, simple but highly useful tools

December 14, 2018 by Frank Xu  

We don’t notice it too often, but the heavy machinery and technology that we are using today wouldn’t have been possible without the use of nuts and bolts. From the very beginning of mankind, nut and bolts have been used for various purposes. Earlier, large bolts made of wood were used. They wore out with time and couldn’t be used with heavy loads. With the evolution of machinery, the requirement for attaching heavy parts lead to the production of metal nuts and bolts, which resisted breakage more efficiently and could bear heavier loads. Since then, various sizes and shapes of nuts and bolts have been manufactured.


So, how are these wonderful tools made? Well the answer to this question is another highly tool called dies and metric tap (or simply taps). A tap is used to cut threads on the inner surface of a hole, creating the female part which acts like a nut. Now-a-days, there are many types of taps available in the market to cater the various needs of the customer. Some of the most important ones are discussed below.


1. Bottoming tap (or plug tap) - This type of tap has almost no tapers (not more than 1-1.5). This taper is used when we need to cut threads in a hole which has already been threaded by a more tapered tap. However, due to the absence of tapers, this tap can’t be used to create a new tap from the beginning. This can only be used to deepen the thread to the bottom.


2. Intermediate tap (or second tap) - The number of tapered threads for this type of threads may vary from 3 to 5. These taps are used to create new threads in an untapped hole.


3. Taper tap (hand tap) - This type of tap has relatively larger no of taps ranging from 8 to 10. Owing to this type of tapering, this tap gives a very smooth and gradual cutting effect. This is highly useful when the material to be threaded is too tough or is delicate.


4. Power tap (swarf) - These taps are designed to be used manually. They must be rotated in the reverse direction at regular period to prevent the crowding of metal chips in the hole which can damage the tap as well as the threads cut. To prevent this, spiral taps have been introduced which automatically drives out the chip. They are generally used for fast, automated taping operations due to their appreciable performance on blind holes.


5. Forming tap- This tap is quite different from the other kinds of taps discussed above in the way of making threads in the hole. While the other taps carved threads into the holes by actually cutting out metal chips, the forming tap does no cutting at all. It literally ‘forces’ the hole surface inwards, transforming it into the form of threads. This type of tap due to its harsh way of working, requires to be properly lubricated during the taping process. Also, it can be used ONLY with relatively softer materials like mild steel and aluminium. This way of taping is used when it is necessary to avoid metal chips which can produce difficulty in the taping process.


With this large variety of taps available, it is very important to choose the right type of metric thread tap in accordance with the type of threading required, the material to be threaded, size of threads required, the mode of threading, and other such factors.


Gaugestools, a metric taps and dies supplier, provides a rich range of taps and dies which will surely fulfill your need for any type of taps and dies.


Contact :

Chenchuan Tools Co.,LTD

Chenbei Industry Zone,

Longgang Road,


China, 435202

Phone:  0714-7321211

Fax  :  0714-7321210