Initial Drilling
The front section acts as a drill and creates the rough hole diameter.
Reamers / Drill-reamer combination tools
Combination Reamers
What Is a Combination Reamer and How Does It Work?
A combination reamer merges drilling and reaming into one cutting tool. This drill-reamer architecture creates the initial hole and then finishes it without a tool change or separate indexing step.
Progressive Reaming
The following fluted section sizes the newly drilled hole to its final dimension.
Common-Axis Alignment
Both cutting sections share an axis, which reduces the alignment variation that can occur between separate drilling and reaming setups.
Key Features and Benefits of Combination Reamers
Integrated Design
Combines drilling and reaming to reduce cycle time.
Common-Axis Cutting
Limits alignment differences between the drilling and finishing sections.
Fewer Tool Changes
Reduces machine idle time between drilling and reaming.
Optimized Flute Geometry
Supports chip evacuation from both cutting zones.
Custom Profiles
Can incorporate stepped diameters, tapers, or application-specific bore profiles.
High Rigidity
Is designed to resist deflection under the combined drilling and reaming forces.
Combination Reamers Specifications
| Specification | Range / Details |
|---|---|
| Diameter Range | 1/8" to 1-1/2", with custom diameters available |
| Drill Section Type | Twist or point-ground geometry |
| Reaming Section | Straight, spiral, or step profiles |
| Shank Type | Straight, Morse taper, or Weldon |
| Tolerance | Precision ground to OEM or customer specifications |
| Number of Flutes | Variable according to tool diameter |
Materials and Coatings Available for Combination Reamers
| Material / Coating | Best For | Key Advantage |
|---|---|---|
| Solid Carbide | High-speed, high-volume production. | Provides hardness and wear resistance for continuous cycles. |
| Cobalt Steel (HSS-Co) | General-purpose use and interrupted cuts. | Provides toughness and heat resistance during drilling. |
| Titanium Aluminum Nitride (TiAlN) | Dry machining and demanding cutting conditions. | Can reduce friction and material buildup on the cutting edges. |
Solid carbide provides wear resistance for stable high-volume production, cobalt steel adds toughness for general and interrupted cutting, and TiAlN can reduce friction and material buildup.
Which Machines Use Combination Reamers?
CNC Machining Centers
Run automated drilling and reaming in a single tool cycle.
Transfer Lines
Use combination tools to reduce cycle time in high-volume production.
Turret Lathes
Finish holes in rotating cylindrical workpieces through automated cycles.
Applications and Industries for Combination Reamers
Automotive Sub-Assembly
Drills and finishes mounting holes in engine components in one cycle.
Aerospace Fastener Preparation
Creates and finishes holes for close-fitting aerospace fasteners.
Mass Production Lines
Combines two cutting steps to reduce cycle time and increase automated-line throughput.
High-Volume Components
Supports production where cycle speed and hole-to-hole consistency are key process requirements.
Frequently Asked Questions About Combination Reamers
What is the main advantage of a drill-reamer tool over two separate tools?
Combining both operations reduces cycle time and keeps the drilling and finishing sections on the same axis without a tool change.
Can a drill-reamer combination be used on different materials?
Application-specific tools can be designed for materials ranging from mild steel and aluminum to hardened stainless steel and aerospace alloys by selecting the appropriate substrate and coating.
What are the limitations of a combination reamer?
The drilling and reaming sections experience different wear patterns, so tool life can differ from dedicated single-purpose tools. The cycle-time benefit must be weighed against that wear behavior.
What setup factors affect drilling and reaming accuracy?
Machine rigidity, a precision tool holder, and coolant flow that clears chips from both cutting zones affect the resulting alignment and size.
Can a combination reamer be customized for stepped holes?
A custom tool can combine multiple stepped diameters, tapered features, or specialized chamfers in one cutting sequence.
Shared engineering resource
Design and Engineering Support
Bauron provides design and engineering support for custom combination-tool diameters, step or taper profiles, shanks, flute geometries, substrates, and coatings. Share the complete hole print and cycle requirements for technical review.
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