5 steps to selecting the right solid round tool

Dec 21, 2023

Optimized solid round tools, like this CoroMill Plura end mill, can be modified for specific applications. Such tailor-made customizations can extend tool life, improve performance, and reduce downtime.

If a shop chooses the wrong solid round tool (SRT) for a job, it can cost way more than simply its price. Selecting an inappropriate tool can reduce efficiency as well as increase scrap and waste invested time if a workpiece is damaged. When components cost thousands of dollars apiece and go through numerous processes to machine, it pays to get the right tool the first time around.

Machining today's components is complex. Many of them have intricate features and are made of exotic materials that resist heat and wear tools more quickly. As components become more challenging to machine—and the stakes are higher to get them right—getting by with a good-enough SRT is no longer good enough.

But there are literally thousands of SRTs out there, with many new options specifically engineered for heat-resistant materials and distinct component features.

So how does a machine shop find the most effective tool for its application without spending hours doing it? Following a basic, 5-step methodology makes it possible to quickly and confidently choose SRTs that improve quality, precision, and productivity in shops of all sizes, as well as save money over the life of the tool.

Are you milling, drilling, tapping, reaming, or threading? This step might feel obvious, but it's necessary. It helps narrow down the choices for the tool, style of tool, or tool family you’re looking for.

When shops skip this step, they don't have all of the information they need to make the best choice.

For example, a shop that's adding holes to a 3D-printed titanium component might pick a drill meant for aluminum, or a shop that's tapping hard material may get a tap that's for soft steel. This usually happens if there's a disconnect between purchasing and the shop floor. When engineers and machinists aren't part of the purchasing process, a tool might be chosen based on price rather than its capabilities.

To find the most appropriate tool for a job, it's crucial to ask questions about the component and machining demands, such as:

The more you understand about what you want to achieve with the drill, tap, end mill, or reamer, the faster and more exact you can be when choosing your SRT.

There are a couple different ways to make this analysis easier. One is to directly engage your tool provider. These experts already know the questions to ask about your application, as well as the capabilities of available tools.

Sandvik Coromant's CoroDrill 860 is an "optimized" solid round tool for numerous materials that maximizes productivity by improving metal cutting efficiency.

Let's say that you ask your tool provider for a ¼-in. drill, but they have 50 of them, each with different capabilities. The more information you provide about your specific application, the quicker they can help you find the few tools that best match the material you’re working with and what you’re trying to accomplish.

You also can use your provider's tool guide to help analyze your application and quickly narrow down tool selection. Usually available online or as an app, these guides intuitively walk users through a list of questions about their component, then provide a recommendation. Comprehensive guides also provide estimated tool life, horsepower requirements, and specifications for speeds and feeds.

Once you’ve narrowed your selection to just a few tools, it's important to refine it based on production factors and key performance indicators. To meet the varied production demands and goals of numerous customers, some tool providers segment their broad solid round tool offering into groups. At Sandvik Coromant, for example, we call them versatile, optimized, and customized.

Versatile tools are cost-efficient and provide application flexibility. These tools are best for small-batch jobs and shops with high changeover, such as a job shop that machines aluminum one day, steel the next, and cast iron the day after that.

Optimized tools offer greater efficiency, reliability, and durability. The goal of these tools is to save money over the life of the tool. Consider high-volume automotive work. A shop in this industry may be drilling a hole in a million identical parts. This shop will want a specific drill that provides the highest quality, best finish, longest tool life, and lowest cycle times. If a tool drills a better hole five seconds faster than a typical drill, that's a huge time and cost savings over a million parts.

It's important to investigate your tool provider's portfolio. A provider with a comprehensive offering of tools is more likely to get the tool you need up and running on your machine more quickly. If a standard offer isn't available for your machining demands, a customized option may be best.

Customized tools, often called specials, are individually engineered and manufactured for unique machining demands. While advanced engineering may be required to create a tool from scratch, customized tools often are built off optimized tools.

For example, one of our customers was using an optimized end mill on a titanium component that performed well, but we felt that a couple of design updates could considerably extend the tool life. So we shortened the overall length of the end mill, strengthening it, and added radial coolant to better saturate the point of contact.

Those tailor-made customizations tripled the life when compared to the original tool and reduced changeover and the resulting downtime. Because the machine could run three times longer, the shop could start lights-out machining.

It's not enough to look at the upfront cost of a tool. It's critical to consider how the tool will affect how much it costs to produce a component. If a cheaper tool doesn't do what you want to achieve and increases downtime, you may be spending more money over the long term.

Choosing a solid round tool isn't the end of the selection process. The next step is properly applying it. A shop can choose the best SRT in the world, but if it isn't running at the correct parameters, or if other factors are off, it's not going to achieve optimal performance and may not meet the estimated lifespan.

The parameters in an SRT's window, including speed and feed, are obvious. However, the outside factors that affect a new tool's performance and lifespan might not be. They include the holder, fixturing, and coolant. If a shop gets a new end mill, for instance, it's important to consider radial engagement as well as the coolant and its concentration. If the coolant isn't at the recommended concentration level, the tool wears prematurely.

Just like when choosing a tool, a shop should directly work with its tool provider to ensure the proper application of the new tool. Machinists also can use online tools to get proper speeds, feeds, and other parameters.

Reconditioning worn SRTs provides significant cost savings without sacrificing performance. Most SRTs can be reconditioned, but not all reconditioning is equal. Look for a tool provider that offers in-house reconditioning in certified centres that are equipped with the latest technology. Certified reconditioning guarantees like-new specifications, something most local shops aren't equipped to do, for about one-third the cost of a brand-new tool.

Some tools can be reconditioned successfully multiple times, increasing cost savings. Drills typically achieve like-new performance on up to three regrinds, while end mills may show a small drop in performance after the second regrind because it changes the diameter. With up to three regrinds, reconditioning tools is a significant opportunity for savings without sacrificing performance.

Selecting the right solid round tool doesn't have to be mysterious or time-consuming. It starts with a solid understanding of the job at hand and is strengthened through partnership with an expert tool provider.

This combination, plus a dependable selection methodology, ensures you can reliably choose SRTs that improve component quality and production efficiency as well as reduce costs and downtime—every time.

Jim Nielsen is round tool specialist for Sandvik Coromant, 2550 Meadowvale Blvd., Mississauga, Ont. L5N 8C2, 800-268-0703, www.sandvik.coromant.com.