Industrial Engineering

Different types of punch and their functions

In an engineering workshop, after you’ve finished drawing lines on a work with a scriber or a surface gauge, you’ll need a variety of punches to make these markings permanent, because the lines drawn with a scriber may be damaged. For a long time, numerous types of punches have been used in various industries’ workplaces. A punch is often a stiff metal rod with a sharp tip on one end and a dull end on the other.

Carbon steel or tool steel are commonly used for these punches. To correctly cut and shape them, they are utilized in conjunction with tools such as a hammer and chisel. Punches are often classified by the shape of their points. If you’re looking for a punch for your job, here are a few different types of punches and how they’re supposed to be used.

In this article, you’ll learn the various types of punches and how they use.

types of punch tools

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Types of punch tools

The various types of punch tools are center punch, prick punch, solid punch, transfer punch, drive punch, pin punch, roll pin punch, hollow punch, dot punch, bell punch, latter stamps, tablet punch, and automatic punch.

Centre punch

These types of punches are constructed from high-carbon steel. These are hardened and subjected to a tempering process. Their handle is knurled and their point is fashioned at a 90° angle. It measures 35 mm to 125 mm in length and 4 to 12 mm in width. Their primary purpose is to create a center at the drilling location so that the drill bit’s point can correctly rest there. There’s a danger the point will slip and you’ll drill in the wrong spot if you don’t use a center punch to make this center. The figure shows an example of this type of center.

center punch

Drive punch

If you want to remove broken rivets, bolts, or pins that are tied into the holes, you should use a drive punch. A drive punch has a flat face rather than pointed ends. And because the sides of this punch taper the face, you may need to utilize a punch with a straight shank in some circumstances. A pin or drift punch is another name for a straight shank punch.

 

Pin punch

These types of punches differ from other punches in a number of ways. It has a longer length than most. These are parallel in shape rather than pointed. It’s utilized for pins with a tight fit. Pin punches have the ability to fully turn rivets and pins out of a hole till they exit the hole, which other punches cannot achieve. In Figure, a pin punch is shown.

drive pin punches

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Letter stamps

Although they can be made as a positive image, the letter stamps are in the form of a reverse image, making the end output instantly readable. A number or letter stamp is another name for it. Punches of this type are used to turn a letter or number print onto a workpiece. This is required for dyeing or forming molds, and it ensures that the completed product is readable.

letter stamp punch

Tablet punch

The tablet press is another name for this punch. Tablet press punches, unlike most punches, have a curved end that conforms to the desired tablet shape. The powder is compressed between the lower and top punches of this tablet press.

 

Automatic punch

This is a unique type of punch as well. It is made of hardened or tapered high carbon steel. This punch does not require the use of a hammer. A spring is attached to the main punch’s body. A lever head keeps the spring in place. Its lever head is pressed when marking is to be done. The major punch would be squeezed and the marking would be done as a result of this pressure. With the lever head, you may limit or control the punch’s blow. Its main punch has a 60° or 90° angle to it. The figure shows an example of this style of punch.

automatic punch

Roll pin punch

The roll pin punch has a tiny protrusion in the middle of the pin tip that holds the roll pin’s periphery. These types of punches have a not-so-flat tip and are used to drive roll pins. Spring punches are also popular. When utilizing a roll pin punch, make sure the roll pin punch’s shank axis is parallel to the roll pin’s axis. Do not use one side of the roll pin punch to shut it. If you hit a roll pin punch on the top of its head, it will bend the shank.

roll pin punches

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Hollow punch

As illustrated in Figure, it is a particular form of hardened steel punch with hollowness. It’s used to pierce metal, cardboard, and fabric. These come in a variety of sizes and come in different sets. The metal that is cut with them falls out through the grooves built into their side since they are hollow. As a result, we can make a large number of holes in a short amount of time, and the holes are quite clear.

hollow punches

Dot punch

This is identical to the Centre Punch in most ways. The primary distinction is that the point is at a 60-degree angle. It is used to make scribes’ markings permanent so that they do not obliterate during the course of labor. Its length ranges from 80 to 100 mm, and its thickness ranges from 3 to 5 mm. The figure depicts the situation.

Dot punch

Bell punch

It has the shape of a little bell, as its name suggests. The circumference of the bell is used to determine its size. It’s used to pinpoint the center of circular jobs and to mark them lightly. A punch, similar to a center punch, is fastened in this perimeter with the help of a spring. Its head is pounded with a hammer to activate it, and it elevates on its own due to the punch spring.

bell punch

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Prick punch

The prick punch is also composed of high carbon steel and is hardened and tempered. It has a 30° angle to its point. It’s used to drill holes in thin metal sheets or mark them on tasks. It is depicted in Figure.

prick punches

Solid punch

Boring holes using solid punch tools are common in blacksmithing and sheet metal activities. Depending on the job, these are employed in various measurements. These are made of high-carbon steel that has been hardened and tempered. It is critical to cool things down with cold water after using them in heated situations. These are utilized in rough work since holes punched with a solid punch aren’t always accurate and aren’t always clean.

solid punch

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Transfer punch

The normal length of these types of punches is 4 inches, which is long enough to alter the hole position via a pattern or template on the material. A non-tapered transfer punch has a set outside diameter. You can tighten the tolerance of an actual hole by utilizing the transfer punch, and it will adequately transfer the center of that hole to another surface when struck. This can also be used to align the drilling and tapping holes in a template so that an object can be fastened to a surface.

Transfer punch

Conclusion

Punch tools are great tools to consider in any workshop including woodworking and metalworking. They are used after scribing or making lines on the surface of a workpiece. That is all for this article where different types of Punch tools are been discussed. I hope you learn a lot from the reading, if so, kindly share with other students. Thanks for reading, see you around.