A.T. Wall Co. shares its thoughts on how metal stamping can be a solution for cost-effective manufacturing of high-tolerance parts
February 28, 2013
The days of 1 million unit orders for simple metal blanks are over. But this doesn't mean that stamping can't survive in today's manufacturing environment. A.T. Wall Co. believes it can successfully position stamping as a go-to manufacturing process for parts that were at one time exclusively made through machining.
A.T. Wall Co., Warwick, R.I., has produced plenty of metal stampings during its existence.
It was founded in 1886 as a supplier of metal parts to jewelry-makers on the East Coast. Eventually the jewelry industry moved overseas, so the company reinvented itself as a supplier of seamless, cold-drawn specialty tubing and metal stampings.
In a way, the reinvention efforts continue to this day as the company works to exploit the skills of its engineering staff, looking to showcase how it can deliver high-tolerance, high-quality parts with the cost savings associated with high-speed stamping. For example, A.T. Wall has demonstrated that it can pierce small holes in thick materials used to create fuel cell battery tops. The company is able to pierce a 0.078-in. hole through 0.125-in. material. Typical industry production rules suggest that a pierced hole diameter in a metal forming operation cannot be any smaller than the thickness of the material.
A.T. Wall recently shared its manufacturing capabilities at a tradeshow for the battery and fuel cell industry in late 2012. It’s all part of an effort to spread the word that metal stamping can be a cost-effective alternative to other manufacturing processes, such as machining.
Tracy MacNeal, chief strategy officer and executive vice president, and John O’Brien, corporate sales manager, ATW Companies, the parent company of A.T. Wall, shared some of their thoughts about how the company’s approach to stamping has had to evolve and where it is headed in the near future.
STAMPING Journal: Looking at the work that your company has done with stampings in the battery industry, describe how that has evolved.
John O’Brien: “Even going back to the basic A, C, and D batteries, they all have end seals at the top and bottom. Those are all stamped components. Those are standard sizes, and those footprints don’t really change. What does change is the complexity of the part.
“Look at the D battery. At the top, you see it steps up and back down again with the top being the contact point. That’s a very basic stamping. But if you look at the battery business, there might be an application that calls for different holes to be pierced into the battery top for different types of leads to come out of the battery itself. Maybe the top is made out of material that isn’t readily available or people don’t have a lot of experience stamping it. The outside footprint would be the same as the D battery, but inside that footprint would be very different. The tooling for the specialized job is going to be much more complex, and the tolerancing is going to be much more stringent.”
SJ: How has A.T. Wall stayed on top of stamping advancements even as a lot of the high-volume, simple stamping work went overseas?
Tracy MacNeal: “It’s sort of what Switzerland did when they lost their precision watchmaking business when things went digital and automated. They leveraged a lot of that talent into medical devices. They’ve done a good job attracting medical device companies to locate there.
It’s a high-cost place to do business, but they’ve made it very beneficial financially.
“A.T. Wall has done something very similar. As some of the older applications like jewelry-making and battery end manufacturing have gone to Asia, we’ve retained our talent and leveraged them more into higher-end applications like uplinks in mobile phones. Those are very high-precision and very tiny parts.
“So we try and keep up with what kinds of applications are still relevant for that talent pool. The barrier to entry in metals is so much higher than in plastics. The ability to make high-tolerance metal parts at an affordable price is really tough.”
SJ: Can you provide an example of some of the stampings A.T. Wall produces now that stand out as being different from what they were several years ago?
JO: “A lot of the crystal headers that we’re making now, as well as the transistor outline headers,have been around for years and years. These industry standard products originally started as military components and branched out to consumer markets by maintaining consistent outside dimensions we’ve been making for decades.
“What we’ve seen happen is that when new electrical engineers come in and they want to design something, they go to their catalogs and look at what is currently available. They’re not going to reinvent the wheel. They look at a size or profile that fits their needs and then say, ‘OK, that’s very close to what I need, but I need it to have a scribe mark in it because I need to locate it with optical recognition equipment. I also need a downslat in the center because I have to mount some type of light-emitting device.’ All of those things are additions that never existed years ago, but they exist now. These added steps have enabled
A.T. Wall Co. to produce product that continues to meet the requirements of the rapidly changing electronics industry.
“There’s a big push now for near-net stamping, where the goal is to have as little scrap as possible, which is a big improvement when compared to machining. Also, there is a sheer speed advantage that stamping has over machining. I could have a part, put holes in it, and form basic designs and run that part at 200 strokes per minute. When you think about that and compare it to CNC machining, that’s a significant cost savings in time. So if I could get a basic outline with some holes through it and some coined-in features and get somebody 60 to 70 percent of the way there before other processes are needed, that’s a great cost improvement for them.
“The other thing is to take something designed for machining and make it into a stamped part. I do have a customer we were very successful with. We took a $5 machined part and made it now a $1.25 stamped piece. It’s got drawing and coining, there’s a lot going on. It’s a very involved part. I don’t want to mislead you. That was not a slam dunk. That was years of development working with the right customer that had the mindset that said, ‘I believe in you and will follow you to the end. I want to see that cost savings at some point.’ That wasn’t done in a matter of just 16 weeks.”
SJ: It sounds like metal stamping plays an important role in helping customers rethink the way they can manufacture their parts, but it also sounds like it is only one piece of the puzzle. Is that correct?
TM: “One of the things ATW has learned over the last five years is that the primary benefit we offer is having all those different types of metal forming in one talent pool. We’re machinists. We’re also stampers. We do metal injection molding. We draw tube. We fabricate. We do wire EDM. Anything that’s involved in metals, we’re involved in. So we can mix and match where it makes sense.
“The reason a lot of designers start with machining is that it’s something they know. When you’re starting out with a product and you don’t really know what your volumes are going to be, you just need to get your prototypes done. Machining is the easy thing to do. Then to revalidate it or change supplier, it becomes more trouble than it’s worth for a lot of the engineers involved. That’s where you end up with a purchaser who inherits it four years later, and it’s not necessarily the same project anymore. Working with a metal house to take a project through multiple phases is one of the ways a metal forming company can add value.”
SJ: Where do you see A.T. Wall going with stamping in the near future?
JO: “Going forward, that near-net stamping is where we’d like to take stamping while incorporating our machining.”
TM: “The designs are more complex. They’re getting smaller. There’s this concept of mass customization, so you’re not getting as many things that are so standardized where you can crank out 5 million of them a day.
“On the other hand, we see countless projects every year where the volumes are in the hundreds of thousands. If you can get 80 percent of the way there with stamping and then in-house touch-up to get it the rest of the way there, that’s good. You’re still getting a lot of the raw material savings by cutting away material and scrap, and you’re also getting the speed. That’s where we see our strategy going.”