Fast and efficient, metal punching is one of the main fabrication techniques we use to shape and form bespoke parts and products for our customers. But exactly what’s involved? Read on to find out more about the metal punching process and how a CNC punch press works.
Looking for an experienced metal fabrication company that offers high-quality CNC metal punching services in Wiltshire? Call us on 01225 753 894 or send us an email to find out how we can help you and request a free quote.
What’s on this page
- What is metal punching?
- The CNC metal punching process
- What is metal punching used for?
- What types of metal can be punched?
- The benefits of sheet metal punching
- Metal punching services in Wiltshire and beyond
What is metal punching?
Metal punching is a popular cutting technique in which a tool known as a punch press is used to remove material from sheet metal. It’s called punching because the machine effectively ‘punches’ holes or indents into the workpiece. A crucial part of the fabrication process, metal punching can produce a variety of different shapes and cutouts, from simple circles to dimples and complex 3D designs.
Most punching work today is performed using computer numerically controlled (CNC) punch presses, which are renowned for their ability to create precise, repeatable cuts quickly and efficiently.
The CNC metal punching process
Before any cutting can begin, the custom part or product is designed using CAD/CAM software such as Solidworks. The design is then converted into a CNC program that the punch press can understand, for example, G-code. This program is essentially a digital set of coordinates that determine the movements of the punch across the workpiece.
As part of this process, the software checks the design for errors, chooses the right parameters and calculates the most efficient layout to minimise material wastage.
As for the metal punching itself, the process is relatively simple. Firstly, a piece of sheet metal (stainless steel, aluminum etc) is positioned between the punch die and the punch. When the CNC program is launched, the punch press moves down and pushes through the workpiece into the die.
The surrounding material is sheared away and a hole in the shape of the die is left behind. Any scrap pieces of metal (known as slug) are usually collected and recycled. The process is then repeated until the desired shape or form is achieved.
A punch press can cut a variety of intricate shapes in sheet metal
What affects the quality of the cut?
While most CNC punch presses are capable of producing very high-quality cuts and shapes, there are a few factors that can affect the final finish. These include:
- The type of metal that’s being punched
- The thickness of the metal (it’s easier to achieve a neater finish on thin metal)
- The amount of force the punch press can apply
- The size and shape of the die and press
- The condition of the tools (well-worn tools won’t produce as clean a cut).
With decades of experience in punching and metal fabrication, our Wiltshire-based engineering team know how to get the best possible results. However, if you have any questions or concerns simply get in touch and we’ll be happy to help.
What is metal punching used for?
Sheet metal punching is a very versatile fabrication technique that can produce a variety of cutouts and 3D forms. In addition to punching basic geometric shapes like circles and rectangles, a CNC punch press can be programmed to use a combination of single and overlapping hits to create highly complex geometries too.
As well as perforating shapes and holes, punch press machines can make a range of 3D forms such as:
- Dimples
- Louvres
- Threads
- Hinges
- Taps
- Knock-outs.
A punch press can be used to put taps into sheet metal parts
It’s no surprise then that sheet metal punching has become one of the most common methods used by manufacturing companies today. From electrical enclosures and telecommunication cabinets to industrial tread plates, the technique has a wide range of applications across various industries.
What types of metal can be punched?
At Knees Engineering, we can punch a variety of sheet metals, including:
- Stainless steel
- Mild steel
- Aluminium, including pre-painted aluminium
- Copper
- Brass.
We’ve also successfully punched plastic products made from Nylon, PTFE and HDPE. The maximum size we can punch is 4m x 1.27m and thicknesses between 0.5 mm – 6 mm. You can read more about CNC metal punching services in Wiltshire on our website.
The benefits of CNC sheet metal punching
Some of the advantages of CNC sheet metal punching include:
- Speed – Like many other computer numerically controlled processes, CNC punching machines can perform the same task much faster than a human operating a manual punch press.
- Repeatability and consistent quality – CNC punching is a highly repeatable process, which makes it ideal for large batches. It’s also exceptionally accurate, meaning every workpiece will match the prototype’s specifications exactly.
- Increased productivity – The speed, repeatability and lack of manual involvement increases productivity and operational efficiency
- Minimal waste – CNC punching machines are designed to optimise material usage, so any waste is kept to a minimum. This is crucial in helping to keep raw material costs down.
- Flexibility – From cutting to embossing, punching is a very versatile process that can produce a wide variety of shapes and 3D forms.
To discuss whether metal punching is the best option for your next project, please contact us.
Metal punching services in Wiltshire and beyond
At Knees Engineering we use an Amada AE 2510NT CNC Turret Punch Press, which has a positioning accuracy of ± 0.1mm and a press capacity of 200 kn. With the ability to deliver up to 370 hits per minute on one-inch centres and high-speed marking of up to 900 hits per minute, it enables us to produce a wide range of parts quickly and economically. Computer-assisted part nesting also means we’re able to maximise material usage and provide customers with a punching service that’s both efficient and cost-effective.
The Amada AE 2510NT is both fast and reliable, punching with exceptional accuracy
With more than 60 years’ experience in metal fabrication, we provide high-quality and competitive punching services to businesses from a range of industries. Our experienced team are always happy to embrace a challenge and there’s not much we haven’t seen or done over the years. So whatever your metal punching requirements, we’re here to help.
For added peace of mind, every job goes through a rigorous quality assurance process to ensure we meet the highest industry standards.
Not sure whether your part needs punching or laser cutting? Simply give us a call to discuss your project and our experienced engineers will be happy to advise you.
We’re based in Trowbridge, Wiltshire, but our services are available nationwide.
Read more about our CNC punching services here or to request a free quote, simply email the team at sales@kneesengineering.co.uk. And don’t forget to visit our news section for more metal fabrication information and advice.