Common Materials for Reamers

High-Speed Steels (HSS):

• Types: M2, M7, T15, and cobalt-containing grades like M35 and M42 are used.
• Benefits: Good toughness, wear resistance, and cost-effectiveness for general-purpose reaming in a variety of materials.
• Limitations: May not be ideal for very hard or abrasive workpieces where tool life is a major concern.

Tungsten Carbide:

Grades: Solid carbide reamers offer superior wear resistance. Different grades exist, balancing toughness and hardness.

Benefits: Exceptional hardness, wear resistance, and high-temperature performance. Ideal for demanding applications, high-speed machining, and very abrasive materials.

Limitations: Higher cost and can be more brittle than HSS, requiring careful handling and rigid setups to avoid breakage.

• Powdered Metal (PM):
  
  
• Types: PM-HSS offers advantages over traditionally produced HSS.
• Benefits: Finer grain structure for enhanced toughness, wear resistance, and grindability compared to standard HSS.
• Limitations: Relatively higher cost compared to conventional HSS.

Factors Influencing Material Selection

• Workpiece Material: The hardness and abrasiveness of the material being reamed play a major role in material selection.
• Production Volume: Higher production runs often favor the extended tool life of carbide reamers, justifying their cost.
• Tolerance Requirements: Carbide's rigidity and wear resistance can be crucial for holding extremely tight tolerances.
• Machining Setup: Carbide may require more robust machine tools and workholding to avoid vibrations that can lead to chipping.

Common Coating Options

• TiN (Titanium Nitride): A versatile, gold-colored coating offering general-purpose hardness and wear resistance improvements.
• TiCN (Titanium Carbonitride): A harder and smoother alternative to TiN, improving wear resistance and chip flow.
• TiAlN (Titanium Aluminum Nitride): Provides excellent hot hardness and oxidation resistance, ideal for high-speed reaming and tougher materials.
• AlTiN (Aluminum Titanium Nitride): Similar to TiAlN with even greater hardness and oxidation resistance, suitable for machining very hard materials.
• Multilayer Coatings: Combining different coatings in layers can further tailor performance characteristics.
• Specialized Coatings: Less common, but coatings designed for very abrasive materials or specific workpiece interactions may be used in niche reaming applications.

Factors to Consider

• Cost-Effectiveness: Coatings add cost. Their benefits should outweigh this, especially for reamers where extended tool life is key.
• Workpiece Material: The material being reamed is crucial. Coatings offer the most benefit when machining hard, abrasive materials.

Geometry: Coating complex reamer geometries can be challenging. Uneven coating distribution could impair performance.

Key Areas of Use

Reamers are essential tools for achieving precise hole sizes and smooth finishes in various industries and applications:

General Machining:

• Enlarging pre-drilled holes to exact dimensions.
• Improving surface finish and accuracy beyond what drilling alone can achieve.

Automotive Manufacturing:

• Machining holes for bearings, bushings, shafts, and other critical engine and drivetrain components.
• Ensuring precise fit and alignment of parts for optimal performance and longevity.

Aerospace Industry:

• Creating precision holes for fasteners, pins, and other components where tight tolerances are critical.
• Working with advanced alloys and demanding applications.

Mold and Die Making:

• Finishing holes for guide pins, ejector pins, and other mold features requiring precision.

Firearms Manufacturing:

Reaming chambers to exact dimensions for consistent performance and accuracy.

• Medical Device Manufacturing:
  
  
• Creating precision holes in surgical instruments and implants where tolerances are vital.

Why Reamers are Essential

• Accuracy and Consistency: Reamers achieve more precise hole sizes and tighter tolerances than drilling alone.
• Smooth Finishes: Reaming improves surface finish, important for reducing friction, wear, and ensuring proper fit.

Custom Sizing: Reamers are available in a vast range of sizes, including custom sizes, for achieving specific hole dimensions.

Key Sectors Utilizing Reamers

Reamers are indispensable tools in industries where precision, accuracy, and smooth finishes are paramount:

• Machining and Manufacturing: A core industry for reamers, encompassing:
• General Machining Shops: Reamers are a staple for enlarging and finishing holes in a variety of components.
• Automotive Manufacturing: Ensuring tight tolerances on engine parts, suspension components, and more.
• Aerospace Manufacturing: Precision holes for fasteners, structural components, and assemblies where tolerances are crucial.
• Mold and Die Making: Finishing holes for guide pins, ejector pins, and other mold features with high precision.
• Firearms Production: Reaming chambers and other critical components for accuracy and reliable function.
• Medical Device Manufacturing: Creating precise holes in surgical instruments, implants, and other devices where lives depend on accuracy.
• Tool and Fixture Production: Reamers ensure accurate fit and function of jigs, fixtures, and other tooling.

 Why Reamers Are Preferred

• Hole Accuracy: Reamers consistently achieve tighter hole size tolerances than drills alone.
• Improved Surface Finish: Ideal for applications where friction reduction, smooth operation, or proper fit are critical

Versatility: Reamers come in a wide range of sizes, materials, and geometries to suit various applications

Common Machine Types

Reamers, while versatile, are often used in specific machine types to achieve their full accuracy potential:

• CNC Machining Centers: Provide automation, precision, and the ability to integrate reaming into complex machining sequences.
• Milling Machines:
• Vertical Milling Machines: Versatile for reaming operations at various angles.
• Horizontal Milling Machines: May be used for reaming larger or heavier components.
• Drill Presses: Can be used for basic reaming operations, especially with hand reamers.
• Lathes: Reaming can be performed on lathes for holes concentric to a part's rotational axis.
• Specialized Reaming Machines (Less Common): Dedicated machines exist for high-volume production of reamed holes.

Factors in Machine Selection

• Hole Size and Depth: Larger or deeper holes may necessitate more powerful and rigid machines.
• Tolerance Requirements: Tight tolerances often favor CNC machining centers for their precision and control.
• Production Volume: High volume may justify specialized reaming machines, while lower volumes are well-suited to general-purpose machines.
• Workpiece Material: Harder materials may require slower speeds and more robust machines.

Beyond the Tool: Baucor's Expertise

As a world leader in precision machining, Baucor understands that achieving optimal remaining results involves more than just a premium tool. While specialized reamers might be outside our core offerings, here's how we could support this area:

• Materials Consultation: We guide manufacturers and users on the ideal materials (HSS grades, carbide grades) to match specific workpiece materials and performance demands.
• Geometry Optimization: Baucor's engineers can advise on reamer flute design, cutting edge geometry, chamfer angles, and other factors influencing performance and chip evacuation.
• Coating Expertise: We advise on the suitability of coatings (TiN, TiAlN, etc.) to improve wear resistance and tool life in specific reaming scenarios.
• Machining Process Support: Our knowledge of material removal processes helps us suggest techniques or reamer modifications that improve reaming efficiency and outcomes, even when using standard reamers.
• Focus on Precision: Baucor's emphasis on quality translates into supporting manufacturers in designing reamers that meet the exacting standards of our customers.

Your Reaming Performance Specialists

By partnering with Baucor, reamer professionals gain access to:

• Decades of Machining Expertise: Our understanding of cutting tool principles can be adapted to the unique challenges of reaming.
• Performance-Driven Approach: We focus on the outcomes you need – increased tool life, faster reaming, smoother finishes – to improve overall efficiency.
• Collaborative Mindset: Baucor works closely with you to develop the ideal reamer solutions for your specific needs.

Design Principles for Effective Reamers

Key Design Elements and Considerations

Diameter: Precisely determines the final size of the reamed hole. Must match the required tolerance.

Flutes:

• Number of Flutes: Influences chip load and cutting smoothness. More flutes are generally better for harder materials but may limit strength with small reamers
• Type: Straight flutes are most common, helical flutes aid chip evacuation and can reduce chatter in some scenarios.

Cutting Edge Geometry:

Rake Angles: Often neutral or slightly positive rake angles are used, optimized for the intended workpiece materials.

Relief Angles: Provide clearance and prevent rubbing.

• Chamfer: The angled lead-in at the reamer's tip helps guide it into the hole and influences cutting action.
• Shank Design: Ensures proper fit and rigidity in the machine tool holder. Common types include straight shanks and Morse tapers.
• Material: HSS (various grades) for general use, tungsten carbide for demanding applications and higher wear resistance.

Design Factors Influenced by Application

• Workpiece Material: Harder materials necessitate tougher reamer materials, potentially different coatings, and may require adjusted geometries.
• Hole Size and Depth: Influences reamer rigidity requirements and flute design for chip evacuation.
• Tolerance Requirements: Tight tolerances might require specific geometries, materials, and a focus on machine rigidity.
• Production Volume: Influences material and coating choices for optimizing tool life and cost-effectiveness.