DEFA: Adjustable Chamfering Tool
Swiss Precision Since 1961
DEFA Adjustable Chamfering Tool
The HEULE DEFA tool is a versatile, high-precision solution engineered for modern CNC machining. It’s designed for front and back chamfering—or back-only chamfering—in a single pass, without reversing the spindle or re-indexing the workpiece. Ideal for aerospace, automotive, and heavy-equipment applications, DEFA combines flexibility, speed, and reliability in one compact design.
Controlled Chamfers. Infinite Adjustments.
The DEFA tool gives machinists full control over chamfer thickness with infinitely adjustable cutting geometry directly on the tool. This built-in adjustability allows perfect adaptation to varying bore sizes and project specifications—eliminating extra setup steps and reducing overall cycle time.
Built for Challenging Materials
From Inconel to other hard-to-machine or burr-forming alloys, DEFA is built to perform. Its robust construction and carbide-tipped cutting system ensure clean, precise chamfers even under demanding conditions, making it a trusted choice in industries requiring exceptional accuracy and durability.
Dual Cutting System for Complex Bores
DEFA’s dual-cutting system enables efficient machining of bores with longitudinal grooves, cross-bores, or interrupted cuts. It adapts easily to complex geometries, optimizing productivity and ensuring smooth, consistent results.
Precision Materials. Proven Performance.
Featuring an exchangeable coated carbide blade, DEFA ensures extended tool life and repeatable performance. Its specialized sliding-surface geometry protects bore integrity and thread quality during entry and exit—resulting in consistently superior surface finishes.
Trusted by Aerospace Manufacturers Worldwide
DEFA has earned global recognition among leading aerospace manufacturers for its precision, reliability, and consistent results. Its performance in high-tolerance machining proves its capability in the most demanding production environments.
Available Sizes
Available for bore diameters from 4 mm to 36.2 mm (0.157″ – 1.425″), DEFA covers a wide range of machining applications with reliable Swiss precision.
Experience Precision. Experience DEFA.
Elevate your machining performance with the DEFA adjustable chamfering tool—where precision meets efficiency for next-level manufacturing results.
How Does the DEFA Tool Work?
The HEULE DEFA tool operates by cutting a pre-adjusted chamfer diameter with remarkable accuracy. Its precision-calibrated blades maintain consistent chamfer dimensions across workpieces, ensuring reliable and repeatable results. Designed for both forward and reverse machining, DEFA enhances flexibility and process efficiency in a wide range of manufacturing applications.
Precision in Motion
As the blades engage the material, the feed force drives the cutting edges along the defined chamfer surface. This automatically triggers a controlled radial retraction, which gradually narrows the cutting width and allows exact control over chamfer depth and angle. The chamfer geometry is determined by the blade’s contact surface, enabling easy adaptation to varying project requirements without tool changes or manual adjustments.
Protecting Surface Integrity
A key advantage of the DEFA tool is its ability to preserve the integrity of hole and thread surfaces. Its unique sliding-surface geometry minimizes friction during the chamfering process, reducing the risk of scratches, burrs, or deformation — even in delicate materials or tight-tolerance bores.
Benefits of Using the DEFA Tool
- 🎯 Precision: Consistently accurate chamfer dimensions for superior finish quality.
- 🔁 Versatility: Operates in both forward and reverse directions for multiple chamfering tasks.
- 🧱 Surface Protection: Safeguards bore and thread surfaces, ensuring flawless edge quality.
- ⚡ Efficiency: Streamlines machining by eliminating tool changes and reducing cycle times.
Built for Modern Manufacturing
Integrating DEFA into your machining process elevates precision, safety, and productivity. Its design combines advanced geometry with Swiss reliability—making it a trusted solution for aerospace, energy, and high-performance metalworking where every detail matters.
👉 View more catalogs/videos and technical information for DEFA
How Do I Order DEFA?
1. Determine Your Requirements
Before placing an order, it's essential to identify the hole size and chamfer size required for your machining application. Additionally, consider whether you need front & back cutting or back-only cutting blade options for your specific project needs.
2. Consult the DEFA Catalog
Refer to the DEFA catalog to find the minimum hole column, which helps you choose the appropriate tool holder matching your drill hole size. Ensure that the chamfer diameter requirement aligns with the maximum chamfer capacity of the selected tool.
3. Calculate ØD2 Diameter
Calculate the ØD2 diameter (over the blade) by adding 0.080 inches to the ØD (chamfer diameter). This dimension serves as a suffix to the order number, ensuring the precise customization of your DEFA chamfering tool.
4. Specify Additional Features
If you require the tool with an End Plug, add "p" to the order number. Alternatively, leave the field blank if you prefer a tool with a straight shank. This step ensures that your order includes any desired additional features for optimal performance.
By following these steps, you can confidently place an order for DEFA chamfering tools tailored to your specific machining requirements. Experience precision and efficiency in your machining processes with DEFA's high-quality tools designed to deliver exceptional results.
View Application Data Sheet for DEFA
For more assistance, see our online Tool Selector.
DEFA Case Study
Replacing Manual Deburring of Inconel in the Machining of Aircraft Components
Need help selecting a tool? Visit our online Tool Selector and go to the Locate Agent page on our website to find your local technical sales representative. For more assistance, contact us at info@heuletool.com or 513-860-9900 and we'll be happy to point you in the right direction.
