DEFA – The chamfering tool for high dimensional accuracy
Precision chamfering of tough materials, front and back in One Operation
The double bladed DEFA chamfering tool creates predefined front and back chamfers in a single operation without stopping or reversing the spindle. The chamfer diameter can be adjusted on the tool. The DEFA tool is essentially used for the production of hard-to-machine materials especially when a large burr is involved.
- Front and back or only back chamfering of bores in hard-to-machine or highly burr-forming materials in One Operation.
- Dual cutting system for machining bores with longitudinal grooves, cross-bores and open bores with discontinuous cut.
- Chamfering thickness can be infinitely adjusted directly on the tool, depending on the bore dimension.
- Exchangeable carbide blade with material-specific coating.
- No injury of the bore surface or of the thread during penetration.
Altough the SNAP chamfering system has the same field of application as DEFA, some characteristics continue to make the DEFA chamfering system the first choice. The dual cutting principle and the rigid connection of the two DEFA blades allows chamfering of up to 180° discontinuous bore edges. Also bores with cross-bores can be passed without stopping rotation. As a consequence, the DEFA chamfering system is ideal wherever bore edges are discontinuous due to grooves, beads, lateral cuts, etc. DEFA chamfering systems are ideal for processing hard-to-machine materials such as titanium, Inconel, Rene and other nickel-based alloys. In the aircraft industry, chamfer diameters must often be produced to tight tolerances. With its infinite adjustability, the DEFA tool can be adjusted exactly to the required dimension. The selected blade diameter determines the chamfer size regardless of the cutting force. This ensures high reproducibility and process reliability.
Chamfering is carried out from the same side as previous boring. The two DEFA blades can be retracted radially into the blade housing. Inside the blade housing, they are held by a control system allowing them to deflect. At the same time, the DEFA blades are rigidly interconnected through the control system. First, the DEFA blades completely remove the burr. Then they meet the work piece surface and retract automatically and synchronously back into the blade housing while the chamfer is being cut. When the blades are retracted, the DEFA tool moves into the bore with the spindle rotating. The control system reduces the cutting force to a minimum. This rules out any damage to the bore surface or a thread. When moving out of the bore, the blades return to their home position and are interlocked. The back bore edge is now deburred and chamfered by backward feed.
The DEFA assortment is comprises of 4 tool series. Within these series, various diameter graduations are available which cover a small bore diameter range. For details on the assortment, please see the catalog.
|Tool series||Bore||Chamfer size|
|DEFA 4 – 6
||Ø 4 – Ø 6.6
||0.1 – 0.6
|DEFA 6 – 10
||Ø 6.0 – Ø 10.1
||0.1 – 1.0
|DEFA 9 – 24
||Ø 9.0 – Ø 23.9
||0.1 – 1.5
|DEFA 21 – 46
||Ø 20.7 – Ø 45.5
||0.2 – 2.0