Punches are one of the striking tools that have a history of hundred years ago. It is highly versatile and available in various types can be used in many industries for multiple applications. A punch is a hard metal rod with a sharp and narrow tip at one end and a flat/dulled end we known as ‘head’ at another side. The narrow tip is used to point against a target object and the flat end is struck with the hammer or chisel to create a cut or shape the object. There are few common types of punches available such as prick punch, center punch, drift punch, and pin punch. We normally use punches to create holes in the sheet metals, it can also be used for drawing circles, starting holes for the drilling process, transferring the location of holes in the required pattern, and removing damaged bolts, rivets or pins. Punches can be classified by the shapes of their point and each has specific applications and functions.
1. Center Punch
A center punch, also known as Diagonal Punch, is used for marking the center of a point when drilling holes. Before drilling the hole in the object, we can use a center punch to mark the area where the drill bit will enter for drilling purposes. It provides a marking that guides the drill bit to create the desired shape efficiently and correctly without walking away. The Center punch is heavier than the prick punch and has a point ground to an angle between 60 degrees and 90 degrees. For some metal works that required a larger indentation, a center punch is a perfect choice to perform this task as it can make the reference marks large enough for the drilling works. An automatic center punch is also available and it does not require the use of a hammer for creating the marking.
2. Prick Punch
Prick punch, also known as ‘Dot Punch’, is the most common type of punches that widely used by professionals. It creates a light marking on the metal with a small hammer. Due to its light indentations, it is suitable for use on soft materials like plastic, wood, or soft metal. We normally use prick punch to remark the reference mark on the metal or wood when transferring a pattern from the paper/drawing to a workpiece for fabrication or cutting purposes. This can be easily done by placing the paper right on top of the workpiece and tapping the punch slightly with the hammer to outline the pattern on the workpiece. A light indentation will then be created without damaging the workpiece. When using the prick punch with the hammer, we need to be careful and never take a heavy blow on it as this may bend or damage the prick punch.
3. Drive Punch
We will need to use drive punch for driving out the bolts, rivets, or pins that are bound up in the hole. It consists of a flat surface instead of a tip point at one end. The size of the flat surface determines the type of punch such as 1/4 inches or 1/8 inches.
4. Pin Punch
The pin punch has a straight shank and it is mainly used for finishing the drive-out process of bolt, rivet, or pin. After we use the drive punch to drive and loosen these fasteners, we can then use a pin punch to drive them out until they are fully ejected from the hole. The removal of bolts or pins from the hole cannot be merely done by a drive punch as it requires the use of pin punch to finish the whole process.
5. Transfer Punch
As per name suggests, the transfer punch is used for transferring the location of holes to the metal via a pattern or template. It typically has 4 inches long and comes in a set with a different diameter. The outer diameter of the punch is the size of the current hole. It has a pointy tip that similar to the prick punch located at the center position of the punch used to point out the center of the hole. It is very good at transferring the center of the hole precisely to another workpiece
6. Aligning Punch
Aligning punch is used for aligning two or more holes for the insertion of fasteners like bolts or rivets. It is gradually tapered and its body allows the holes to be gathered and aligned correctly as it is inserted. Aligning punches are not allowed to be struck by a hammer and cannot be used for driving the fastener.
How To Take Care Of The Punch Tool
We need to take several steps to take care of the punch tool and maintain its quality. Firstly, we have to clean punches after each use with a clean rag. Secondly, apply a light layer of oil coating on the punches before storing it at the place. It is required to be stored properly in the toolbox, racks, or tool rolls to prevent any damages to the edge. Additionally, we need to replace the punches that have mushroomed ends or when it is cracked, bent or chipped as it is very dangerous to use, it may cause bits of metal to fly off if the tool is stuck and hurt ourselves.
There are different types of punches for a wide variety of works. Some types are used for creating indentation on the workpiece, some are good at driving out the fasteners. While some decorative punches are used for creating patterns or images. By choosing the right punches, we need to consider our purpose, applications, and the required size and material type of the object. Not every punch can be used for hard materials such as steel and some are only suitable for soft materials. In addition, if we are working in a near-sparking working environment, it is preferable to consider the punches made of copper, brass, or aluminum bronze. A wrong application of punches may damage the tool and workpiece. MecHero Malaysia supplies quality punches and other hand tools for meeting your project requirements. You can always contact us at +6011-7000 7687 or email us at my.mechero@gmail.com for an inquiry about the fabrication of a storage tank for industrial use. As a steel and online hardware store Malaysia, we also supply a wide range of steel material, general hardware, or mechanical components. Tell us your requirements now and we can advise you accordingly.
Photo credit: powertoolsdaily, fine-tools, tractorsupply, jegs, itm, trinidad, moglix, mayhew,