For certain machining applications, off-the-shelf cutters come up short. Here’s how to increase productivity, reduce costs, and improve part quality with a custom cutting tool solution.
There are many good reasons for a shop to invest in a custom cutting tool. Combining a center drill, drill, and counterbore into a single cutter, for example, means less time is wasted on tool changes. Stubbing up an end mill or modifying its geometry slightly may make a machining operation more productive and predictable. In those cases where tool stations are limited, a custom tool can make the difference between completing the part in a single operation or not. And as any multispindle screw machine operator can attest, forming a part feature in one shot vs. profiling it produces big dividends in cycle time.
Anyone who’s used a custom tool will tell you that all this and more are possible, but in the same breath warn that you may need to wait weeks or even months for it to arrive, and that you should have a generous tooling budget to boot. And there’s the rub. In these days of ever-shorter lead times and dwindling production quantities, the custom road is one that few job shops care to travel.
This typically puts “custom engineered tooling solutions” squarely and almost exclusively in the domain of automotive and other high-volume manufacturers, where targets for the lowest possible tooling cost per part are second only to reducing cycle times.
That’s unfortunate. Thanks to increasingly capable CNC tool and cutter grinders, and software systems that streamline toolmaking while providing more predictable results, custom cutting tools arrive more quickly and are less expensive than ever before. This makes them a viable option for production volumes once considered too small for specialty tools, or where investment in a custom solution was previously prohibitive. Check out the websites for ANCA, Walter, Rollomatic, or any other brand of tool and cutter grinder and you’ll find options such as ShapeSmart and Tool Studio, software tools that are now an integral part of any tool design and manufacturing process.
“Grinding machine builders are constantly battling to be the top provider of high quality and user-friendly software, which has made a huge difference in the options available to our programmers and setup people when creating complex tool geometries,” said Alyssa Walther, applications engineer at OSG USA Inc. (Bensenville, IL). “Also, simulation software helps us catch potential grinding problems when they’re still in the quoting and designing phase, long before they can affect the production floor.”
There’s more to the grinding story than software, however. Walther explains that workholding has become much more accurate and repeatable over recent years, making tighter dimensional accuracies easier to achieve during cutting tool production. And sophisticated in-process probing and measuring systems not unlike those found on machining centers and CNC lathes allow OSG and other manufacturers to catch out-of-tolerance tools earlier, reducing scrap and manufacturing costs.
Grinding wheel manufacturers play a part as well, continuously fine-tuning grits and bond types for the best performance in specific applications, which in turn increases grinding consistency and minimizes lost machine time due to wheel breakdown. Robotics and other forms of automated part handling also serve to increase production efficiency, just as they do for manufacturers everywhere. The result? Custom cutting tool lead times and prices are reduced, while quality and performance improve.
But what is a custom cutting tool, and what makes it so special? Those who’ve machined hydraulic manifolds will immediately think of the porting tools used to produce SAE and MS-style fluid connections. Though not strictly custom (most are available from stock), these multifunction cutters ream, counterbore, chamfer, and spotface a hole in one operation, and are a good example of what’s possible when shops take the custom route.
The term “custom” is used to describe much more than this mainstay of hydraulic component production, however. It might mean an external grooving tool insert that chamfers the top of the groove after cutting it. It could also be an extended length drill, an end mill with an extra flute or material-specific geometry, a form cutter for a special shape, a proprietary thread form, or a one-off version of the porting tools just described.
“We spend a lot of time developing specialty cutting tools at our tech center,” said Dave Williscraft, manager of the engineering project department at Seco Tools LLC (Troy, MI). “Most of the time this is in response to a customer that says, ‘I need to produce this family of parts in less time,’ or ‘I saw this tool at someone else’s shop, do you guys have something that might work in a similar manner?’ We’ll take those requirements—whatever they are—and do our best to make a tool that meets or exceeds the customer’s expectations.”
Tyler Martin, Seco Tools’ manager of engineering services, agreed. “We’ve had situations where we’ve combined different tools, turning what was three operations into one, for example. That’s a fairly common request, as it not only eliminates tool changes but simplifies the machining process as well, something that’s important with the shortage of skilled operators.”
Many of these are solid-carbide round tools, he said, but there are also special milling and turning inserts, cutter bodies, and proprietary coatings and geometries.
“It’s anything we can do to provide cost savings or throughput improvements to our customers. Whether
it’s an automotive manufacturer cranking out thousands of axle components each day or a small job shop doing aerospace and medical parts, great productivity gains can be made with a custom solution.”
Playing Devil’s Advocate
To be fair, custom cutters aren’t for everyone. Advanced software systems and advanced machine tools may make cutting tool manufacturers nimbler, but even the fastest of them will make you wait a week or two for a special, and probably much longer. This isn’t such a big deal if you’ve been charged with laying out the 2020 Ford Focus transmission machining line, but basically kills any custom tool opportunities if yours is a typical job shop facing routine drop-in orders.
Tooling price is another key consideration, although most industry experts will tell you that cutting tools represent but a small percentage of overall production cost. That, and given the benefits listed earlier, the premium paid for any custom tool is easily amortized given sufficient production quantity.
If not, OSG’s Alyssa Walther offered some excellent advice. “Can you do the job with a standard tool?” she said. “If yes, locate a manufacturer who has one that works and can provide the support needed to run it properly. Not every customer has the same end goal—some need superior surface finish, others need high productivity, while still others need low tool cost. Whatever the reasons, if it’s feasible to use a standard item tool, by all means, do so. It will typically yield shorter lead times and lower costs.”
The other argument against custom tools is flexibility. A multifunction cutter that drills, counterbores, and chamfers might be a huge timesaver, but the cutting speed at the periphery may be too high relative to the tool’s center, especially on difficult alloys. The result could be faster-than-normal tool wear, poor surface finish and increased production costs.
An all-in-one tool also eliminates any possibility of adjusting individual part features. If the tool wears and the counterbore gets a little tight, for instance, there’s no way to offset a combo tool as you would a boring bar. The same can be said for form tools, step drills, custom profile cutters or any tool that generates multiple part features in one step—so depending on the circumstances, conventional tools might the best bet.
Customs for the Customizers
Despite the apparent limitations of custom cutting tools, there’s no shortage of shops that use them, nor of manufacturers that produce them. One of these is Cole Carbide Industries Inc. (Orion Township, MI), which has built its business on customs. “For the most part, we don’t make standards,” said Frank Hebda, vice president of sales. “We much prefer making tools to a customer supplied print, or are happy to design and build an insert, end mill, or whatever’s needed for the customer’s application from start to finish. That’s where we provide the greatest value.”
When asked which industries are buying all these custom tools, Hebda’s answer was, perhaps, predictable. “All of them,” he said. “There are the obvious ones like automotive, but there’s also oil and gas, aerospace, medical, moldmaking—pretty much anyone who buys tools is a candidate for ones that are custom.”
Hebda agreed that the drawback to custom-made tools is delivery time, and it’s a pain that he shares. As volumes increase, Cole Carbide is often faced with its own specialty tool conundrum, as it’s sometimes necessary for the custom tool maker to have custom molds made for pressing the inserts, or even a custom tool and cutter grinder built to produce them.
“When you get up around 10,000 or so inserts, we’ll usually have one of our suppliers design and build a die to press the blank,” he said. “Number one, this saves on carbide costs, but it also reduces our grind time, wheel costs, and so on.”
If the volume warrants, Cole also builds its own specialty grinders. These are multi-axis CNC machines with automated part handling, so even though they’re making customer-specific tools, the process isn’t all that different than that of standard tool production—just load up the machine with blanks and let it run. “The only downside is that these machines aren’t cheap,” said Hebda. “You’re pushing a million dollars or more for some of them, so you have to grind a lot of tools to achieve good ROI.”
Special Orders Don’t Upset Us
If you’re thinking about the extra deep slots in the gear shafts you machined last month, or the recessed pockets in the stainless steel housings you’re working on right now, now might be a good time to order a custom cutting tool—the problem is, where do you start?
Brent Sheerer can help. The director of product management at ARCH Specials, a division of ARCH Global Precision LLC (Bloomfield, MI), he said ordering a custom cutting tool is easier than many people expect. Like most suppliers, ARCH Specials offers a tool design function on its website, and backs its online capabilities with knowledgeable people to help companies avoid ordering tools that generate less than optimal results.
“We have a program called Tool Builder,” he said. “Here you can upload a part print, then answer some questions about the shape and style of the tool you’re looking for, what materials you need to cut, the expected tool quantity, the machine you’ll be using and how you need to hold the tool. If you have a sketch of the tool, great; if not, our internal review process will leverage the many decades of valuable experience available throughout our seven facilities to provide the best possible solution.”
KEO Cutting Tools and ARCH Specials channel manager Dino Fracassi noted that tool design can be an iterative process, and that customers should find a partner willing to work with them as much as is necessary.
“Some customers are more technical than others,” he said. “Oftentimes they have a firm handle on what’s needed, but it’s always a good idea to have an application engineer or tool specialist look at the design and see if it can be improved. It might be as simple as changing a corner radius here, tweaking a rake angle there, or maybe a different tool coating can be applied to make the tool perform better on various materials. Considering that custom tools are usually in it for the long haul, you really want to optimize the design for maximum production.”
Kyocera Precision Tools Inc. (Hendersonville, NC) is another cutting tool provider with its feet firmly planted in custom territory. Kevin Jackson, solution sales specialist for solid round tools, said Kyocera produces a wide range of specialty cutters but specializes in tools smaller than 0.250″ (6 mm) in diameter.
“A good percentage of our special tools are geared towards medical machining—intraocular lenses, surgical suture needles, and the like,” said Jackson. “We also produce a lot of router bits, circuit board drills, and similar small cutting tools, many of which are used in the electronics industry. A number of these are step drills—one recent job had four steps to it, so it could center drill, drill, counterbore, and chamfer, all in one operation. Tools like this offer drastic reductions in cycle time.”
Sometimes, there’s nothing special about a custom cutting tool except that it simply isn’t available otherwise. One case in point is a miniature end mill Kyocera produces for an automotive nozzle manufacturer. The only difference between it and perhaps hundreds of similar catalog items is the tool’s 1xD cut length, which the customer has found increases rigidity enough to justify its slightly higher cost.
Fuel nozzles are made by the tens of millions, and the manufacturing engineers responsible for producing them will take whatever steps are necessary to achieve the perfect process. But what about the guy or gal that needs only a handful of custom cutting tools? Not to worry, said Jackson. “We routinely take small orders, in part because we know that once the customer sees the benefits of a custom tool, they’ll want more of them—what starts out as a 25-piece order frequently grows to a thousand or more as the customer’s business grows. That’s why roughly half of all the tools we sell are specials.”
Buddy Cagle, regional sales manager at YG-1 Tool Co. (Vernon Hills, IL), also sees a booming market in bespoke cutting tools, across all industries. “Automotive probably has the lion’s share, but we’re also quite active in aerospace, energy and general machining,” he said. “Tool consolidation is perhaps the biggest driver for these markets. Anytime you can combine two or three machining functions in a single tool, it’s going to have a significant impact on cycle time, and generally result in tremendous cost savings during the manufacturing process.”
Cagle pointed to a recent success story with a company producing impeller shafts for the marine industry. By creating a roughing end mill with a special chip-breaking geometry, along with an extended length 10xD finisher, a part that once required four separate end mills can now be machined with just two custom tools, in less time.
Like the others interviewed for this article, Cagle agreed that the benefits of custom tools go far beyond cycle time reduction. Machining simplification, making better use of available turret or magazine space, and special forms are the most common justifications, but cutting tool manufacturers (often at the behest of their customers) are constantly designing new tool geometries, carbides, and coatings to bolster machining performance, some of which eventually end up in their standard tool catalog.
Said ARCH Specials’ Fracassi, “Dialing in the geometry on an otherwise standard end mill or indexable cutter can make a huge performance difference, but a lot of shops won’t even think about doing that unless they have huge production volumes. But for a cutter that you use 50 of a year, it might make sense to engineer a solution that works best for your specific materials, machine tools and workpieces. In the long run, this is the most cost-effective way to increase total process performance.”