In many machining environments, drilling and reaming are treated as two separate operations. The benefits of this two-step approach are that it offers flexibility, control, and has delivered reliable results for decades.
However, if you are manufacturing repeating parts involved in high volume machining, working to tight tolerances, or aiming to maximise spindle efficiency, combining those steps into a single operation with a drill reamer combination tool could be a more streamlined solution.
Although combination tools like drill reamers provide convenience, their true value is efficiency. Instead of using two separate tools in two separate passes, a drill reamer performs both actions in one motion with one setup, one toolholder, and one toolpath which results in less programming, fewer variables, and faster cycle times.
Fewer transitions also limit the opportunity for axial misalignment or radial runout between tools. In fact, removing the second tool change altogether, removes a major source of cumulative tolerance error.
Due to the fact that both cutting tool geometries are integrated into the same body, drill reamers achieve a near-perfect alignment between the drill and ream sections.
This results in:
While final hole quality still depends on spindle condition and toolholder accuracy, concentricity errors are significantly reduced versus traditional two-tool setups. That is critical for meeting standards like AS9100 or MIL-HDBK-5J.
At Exactaform, we design drill reamers from ±0.02 mm bores in aerospace structures and clean finishes in composite stacks and aluminium assemblies.
Drill reamers simplify machine setup by reducing the number of tool offsets and wear adjustments required. With fewer tools to monitor, operators can maintain process consistency more easily, especially across multiple shifts or high-volume production runs.
By replacing two tools with one:
Reducing your tool count brings immediate benefits such as fewer toolholders, less inspection and fewer maintenance intervals.
However, paired with PCD cutting edges, drill reamers offer an extended tool life, often 3–5x longer than carbide alone. Their reworkabilty, which has no detrimental affect on performance, offers a tooling strategy where the cost per part can be significantly reduced.
As previously mentioned, drill reamers are built for consistency in repeatable processes with tight tolerances. They eliminate variation by design, helping reduce cumulative error and keep tolerance stack-up in check.
This directly supports improved Cp/Cpk values, making it easier for manufacturers to meet capability targets and quality standards over long production runs.
We’ve seen the greatest impact in operations such as:
If you’re machining repeating parts and working to tight tolerances, a drill reamer could be one of the most effective upgrades you make to your process. At Exactaform, we design PCD and carbide drill reamers around your specific materials, tooling environment, and production goals.
Talk to our team today to explore your options.
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