Buyer Tips: Considerations for Selecting the Right Boring Head

Understanding the Different Types of Boring Tools

There are many ways to make a hole, so let’s start by exploring the different types of boring tools:

Rough Boring Heads

• Designed for removing larger amounts of material
• Built with enhanced rigidity to handle increased depths of cut
• Built to handle higher torque and axial forces
• Efficient for making consistent passes to remove material
• Usually a twin-cutter tool that can be run in balanced- or stepped-cutting configurations

Fine Boring Heads

• Optimized for precise material removal
• Balanced for high-speed cutting
• Perfect for achieving exact specifications

Digital Boring Heads

• Reduces the risk of human error with digital display for precise adjustments 
• Resolution of Ø.00005" (EWE series), which enhances accuracy for tight-tolerances

Automatic Boring Heads 

• The latest innovation with fully automatic adjustment capability (EWA series)
• Performs closed-loop boring operations without a human operator
• Eliminates the need to stop the machining cycle to manually adjust the boring tool

Specialty Boring Heads

• Usually designed to perform multiple operations in a single pass (roughing and finishing, finishing different-sized bores in line)
• Includes accessories for standard boring heads, including back boring, face grooving and chamfering cartridges 
• Can be designed with specific angles to eliminate the need for secondary operations on the part

Drills

• Any tooling with center-cutting capabilities to produce holes from solid materials

Tips for Selecting the Right Boring Tool

You now have a general overview of your boring tool options, but how do you make the final decision? These are our pro tips when assessing boring tool selection:

Application Considerations

First and foremost, you’ll want to consider the applications typical at your facility. If the majority of your operations depend on specific types of dedicated tools, the decision becomes more focused. But for shops that have a wider range of jobs and needs, you’ll want to consider a tooling inventory that is more versatile. For example, multiple insert holder sizes for specific boring heads. Modular tooling comes into play here too: having a range of modular components allows for reconfiguration flexibility. Just make sure your modular components are as high-quality and rigid as possible—as chatter can be a concern in longer modular setups.

Pre-Processing of the Part

How is the part started? Holes that are cast or forged may not be of the ideal size or hole condition for finishing operations. For this reason, you should consider an additional rough boring operation prior to finishing. This not only sets you up for an on-spec end result, but also can prevent you from wearing out finishing tools and inflating tool costs.

Workpiece Material

Harder-to-machine materials not only require specialized inserts with tough substrates and special coatings, but also the right choice of insert geometry. For example, difficult-to-machine materials require sharper cutting geometries. What’s more, long-chipping materials will require a tool assembly with more clearance for chip evacuation.

Stability and Rigidity

Stability is vital in all machining operations, and boring is no different. Start by making sure your machine and spindle aren’t contributing to excessive vibration  and that you are using licensed dual-contact tooling. The more contact you have between your machine spindle and tool taper, the lower the risk for detrimental vibration. Finally, gauge length and boring depth could affect your stability (more on that a little later).

Tolerances and Surface Finishes

The tighter your tolerances and higher quality your surface finish requirements, the more you’ll need to focus on precision boring options. But even when tolerances are slightly more lenient, high-precision tooling can be a boon to productivity and tool costs. Benefits include longer tool life, faster setups and operations and fewer scrapped parts.

Depth and Gage Length

Gage length is the distance from machine spindle to part feature, while boring depth is the actual depth of the hole. Excessive lengths in either of these areas could require longer tool assemblies, which can compromise rigidity, productivity and finished part quality. High-quality modular components can maximize rigidity while maintaining necessary reach, but consider these additional tips:

• Pay attention to the length-to-diameter ratio. When tools extend beyond four times diameter, rigidity can be a concern. 
• If you need extra long assemblies, talk with a boring expert who can provide solutions that will minimize vibration

How to Evaluate the Cost of Boring Tools

The sticker price is NOT the price you pay for your tooling. To the contrary, lifetime cost comes into play here. In this sense, it’s best to measure your cost per hole. How many holes can one tool produce vs. another? Additionally, does one tool allow you to complete jobs faster to take on more jobs or reduce labor costs? This will play into your bottom line as well. In the end, an upfront investment in higher-quality tooling always yields a strong return.

Regardless of your applications and needs, you’ll want to consider working with experts who know boring on a deep level. At BIG DAISHOWA, we wrote the book on boring, so we understand the nuances of your specific operations—and can recommend solutions to solve myriad boring challenges. Talk to an expert today.