HEULE, a world leader in tool development, introduces DEFA tooling which provides a wide range of adjustment for chamfering operations in difficult-to-machine materials like Inconel, Titanium, 4140 Steel, and others with large burr formation. Robust construction and an advanced dual-cutting system with exchangeable carbide blades enable front and back or back-only chamfering of bores from 4 mm to 36.2 mm (0.157” to 1.425”), to handle a wide range of machining requirements. Its unique blade geometry incorporates a sliding surface that enables chamfer cutting without compromising the integrity of the bore surface or interfering cross holes, ensuing surface quality. DEFA enhances precision and streamlines machining processes by eliminating the need for spindle reversal or workpiece indexing. This ensures precision and consistency even in the most demanding applications, such as longitudinal grooves, cross-bores, and open bores with discontinuous cuts. The DEFA Tool compensates for surface variation allowing constant chamfer sizes on unknown or cast surfaces. This versatility enhances efficiency, optimizes productivity, and reduces set-up times, making it ideal for chamfering applications on exotic materials such as Inconel, Titanium, Hastelloy, and other hardened materials. Ideal for Shafts, Compressor cases, landing gear components, and other airframe structures and anywhere precision front and back chamfering of through holes is need.  Automotive applications such as planetary gears with multiple surface variations and burr formation can also benefit from DEFA technology.
This unique dual-cutting tool provides machinists with precise control over chamfer sizes across a range of on-tool adjustments, yielding flexibility to accommodate diverse bore dimensions and project specifications. Featuring an exchangeable carbide blade set with a material-specific coating, the DEFA tool delivers consistent and reliable performance in challenging machining environments.
How it works
The DEFA tool operates by cutting a pre-adjusted chamfer diameter with precision regardless of where the surface of the part is located. Its design incorporates blades that maintain a predetermined setting, for consistent chamfer diameters across workpieces. The unique design and construction of the DEFA blades enables machining in both forward and reverse directions, enhancing versatility in manufacturing processes.
As DEFA blades engage with the material, the force applied through the feed onto the chamfer definition surface triggers radial retraction along the axis of the chamfered surface. This mechanism results in a gradual reduction in cutting width, allowing for precise control over the chamfer dimensions regardless of the height of the burr formation. The chamfer angle is determined by the angle of the definition surface, providing flexibility to adapt to diverse project requirements.  Different Chamfer sizes front & back can be pre-ground into special cutting blades.
A key advantage of the DEFA tool design lies in its ability to safeguard the integrity of the hole. The DEFA tool can produce chamfers up to .050” a side, to produce a large chamfer before the thread or tap, creating a lead for the tap, and ensuring that the chamfer is larger than the OD (Outer diameter) of the thread during the chamfering process. This is achieved through the sliding surface geometry of the DEFA blades, which effectively mitigates the risk of damage, ensuring consistent surface quality.