Not Your Father’s Punching Machine

Do punching machines still have a place in the sheet metal industry?  The answer may surprise you.

During a recent industry event, I was asked an interesting question: Do punching machines still have a place in the sheet metal industry?

The answer is yes – and no. Although I’m not trying to skirt the issue with an ambiguous response, the truth of the matter is that there is indeed some ambiguity involved, and here’s why. The sheet metal fabricating industry is driven by innovation. Its processes are constantly evolving in terms of new technology, new efficiencies, new applications and even new markets. The raw material we work with may be solid steel, but the business we’re in is a fluid one.

And as this industry changes, so do the demands for sheet metal processing equipment. For example, it is becoming ever more popular to fabricate parts with a laser using a single cutting tool that requires little to no setup, change-over, sharpening, or maintenance. Laser cutting is fast, which means that it’s efficient. And efficiency equals productivity equals profits.

We can use a weather analogy to describe the situation: The laser is like lightening, and the punch is more like a steady rain. However, please keep in mind that even though a punch machine may not be the fastest way to achieve your fabricating requirements, it remains the most cost effective means for processing parts.

And more specifically, today’s punch is not your father’s punch. These machines have come a long way from only punching holes. The newest punching machines can rotate all tools, create forms, tap holes, bend parts up to 90 deg, remove the burr from edges, and even provide shear cut quality on parts, all of which eliminates the need for any secondary operations. These efficiencies are very important in the modern manufacturing world, where lot sizes are constantly being reduced and secondary operations add to the cost of parts.

Smart business owners are always searching for new ways to fabricate parts at a minimal cost. Before investing in your next punching machine, here are some things that fabricators should consider:

Some parts punch faster and better. Hole-intensive parts are typically produced much faster on a punching machine than on a laser cutting machine. If a fabricator produces these types of parts on a regular basis, a punching machine would be a natural choice. Volume is the name of the game. In addition, certain applications such as press-fit holes require tolerances that cannot be produced by a laser.

Form your opinion. Louvers, dimples, card guides and extrusions are just a sampling of the forms produced by a punching machine, and as long as these features are required, punching remains the ideal process to produce them.

Lower investment and cost of operation. The out-of-pocket investment and operational costs are lower with punching machines than with laser cutting machines. As competition in the marketplace increases and fabricators look to reduce costs, punching certain parts may prove to be more profitable than laser cutting them.

When all that you have is a laser, everything is a laser part. A great deal of sheet metal components are cabinets, boxes, panels and covers with standard sized holes and not a lot of contouring. By definition, these are not “laser parts”. Depending on lot sizes, many manufacturers realize that the fastest and most cost-effective method of producing them is to utilize punching technology.

Higher production quantities. Although not typical, there are still some manufacturers that run hundreds of parts per production run. With longer runtimes, the faster setup and universal tooling of the laser cutting machine is minimized, and the punching machine may be a wiser choice.

Thin sheet = cost savings. Materials costs are always a significant factor that comes into play when analyzing the cost of doing business. Especially during the past few years, as steel prices have become unpredictable. This volatile fluctuation in market prices makes for difficult planning when it comes to managing a business’ margin of profit. One solution to this problem involves the types of materials you use, and one way to achieve your goal of fabricating parts at a minimal cost is to use thinner gage material.

However, fabricators must be very cautious when laser cutting thin gage, as part rigidity is easily compromised. The solution here is to use a punch machine to produce stiffening ribs or offsets that will add both structural integrity and functionality to the fabricated parts. Also, using the forming and tapping features of a punch machine can help eliminate welding operations and PEM nuts, thus further reducing the time and cost to produce parts.

The growing trend of combination machines. Designers are constantly creating and developing more complex parts with contours and shapes that require laser technology; however, the fastest way to produce a hole is still with a punch machine. This presented a challenge to manufacturers of sheet metal fabrication equipment who needed to provide a solution that provided finished parts with clean edges – and was also fast.

The solution came in the form of combination punch-laser machines, which are an ideal solution for these types of applications. Combination machines allow for internal features or holes to be punched or formed, and external or complex features to be laser cut in order to achieve the quality needed to meet stringent industry demands. The beauty of these combination machines is that they eliminate the need to move product from one machine to another to complete a finished part.

Combination machines bring together punching and laser technology in one system and use the advantages of both processing modes. Standard contours and forming are performed by the punching head; complex contours are cut with the laser. It’s as simple – and as complex – as that.

Automation and combination machines = the perfect fit. Another key focus in the fabrication arena is automation and punching, and combination machines seem to be the perfect fit for using automation during parts production.

Raw materials are introduced to the process and finished parts are cut out from the sheet and deposited into sorting bins or placed in an unload area totally separated from the sheet skeleton. Some machines can even cut up the scrap into small pieces and deposit it into bins for easier handling. Finished parts are neatly stacked, ready for their next operation. This eliminates the need of manually separating parts from a nest, thus adding more value to finished parts.

In summary, punching technology has, I believe, evolved to the point where it is here to stay. Today’s punch machines have scratch-free and forming capabilities, are available in laser-punch combinations, and also offer the ability to add automation to the process. Though the modern punch vaguely resembles the original CNC nibbling technology that we developed in 1967, the technology has been revolutionized to the point that it can fundamentally change and improve your fabricating business.

What’s in store for the future is anyone’s guess. But one thing I do know is that punch does indeed have a future.