Ceramic Fiber Cross-Hole Brush:
Deburring, Descaling, Polishing Cross-Holes

The centrifugal force generated by rotation presses the sides of the ceramic fibers against the cross-holes, efficiently removing fine burrs up to 0.1 mm burr root thickness. These burrs are ground off without damaging the bores. The Cross-Hole Brush can be used, for example, on machining centers, special machines, drilling machines, robots, and more. The ceramic Cross-Hole Brush "Standard" is designed for bores from Ø 3.5 mm up to a maximum of 20 mm.

For larger diameters, the previously used blue ceramic fiber A33 has been optimized, and the cross-section of the fibers adjusted to be more flexible yet simultaneously more stable, allowing them to better conform to the bore wall for large bore diameters from 20 mm up to a maximum of 35 mm. The new ceramic fiber A34 is used in the newly developed "Ceramic Cross-Hole Brush Extra Large."

The "Cross-Hole Brushes Extra Long" operate on the same principle as the standard Cross-Hole Brushes. However, the "Cross-Hole Brushes Extra Long" are designed for deep bores from 140 mm up to a maximum of 370 mm. Since the guide ring must be precisely matched to the main bore diameter, the entire tool consists of three separate parts (brush head, guide ring, and shank), which must be ordered individually. Therefore, please be sure to specify the main bore diameter of the workpiece to be machined when ordering.

The brushes are suitable for both dry and wet machining. The brush head is replaceable and can be easily unscrewed. The shank is reusable.

PROPERTIES OF Al2O3 HIGH-PERFORMANCE CERAMIC

•     Consistent grinding performance thanks to self-sharpening, durable cutting edges
•     Powerful grinding characteristics
•     Excellent surface finishes and deburring results
•     Versatile application, e.g., on machining centers, special machines, drilling machines, robots, and more
•     Flexible fiber rods gently conform to the shape of the workpiece
•     Long tool life, resulting in higher productivity and lower costs

  
The rods of the brushes consist of approximately 1000 bonded fibers with diameters of only a few microns, made almost entirely of abrasive ceramic. The tips of each fiber form the cutting edges, which self-sharpen during use. This creates a uniform grinding effect, leading to consistent and excellent polishing and grinding performance until the end. Unlike wire brushes, the ceramic fiber rods always return to their original shape after machining.

PUSH OR PULL? The feed direction is decisive.

Sometimes we are asked why, under certain conditions, the Cross-Hole Brush should be retracted first during machining rather than pushed forward first...

The tips of each ceramic fiber are the cutting edges. These must be properly aligned to effectively remove the burrs at the burr root. Therefore, it is crucial that the feed direction (i.e., forward or backward) is correct.

	1. ENTRY MOVEMENT Insert the tool into the bore with the spindle stopped.
	2. START THE WORKSPINDLE Start the spindle rotation clockwise inside the bore just before the cross-hole to be deburred.
	3. FORWARD & BACKWARD MOVEMENT Move the fiber rods in front of and behind the cross-holes. During the backward movement, we also recommend reversing the spindle rotation direction.
	4. RETRACT FROM THE BORE The spindle rotation must be stopped before the tool exits the bore.

 

THE LOGIC BEHIND IT

WRONG If the rotating brush is pushed forward first toward the cross-hole, the fibers can push the burr into the cross-hole. If the brush is then moved backward toward the cross-hole, it can no longer reach the burr root. Even repeated back-and-forth movements of the brush cannot remove flattened burrs on the edge.

CORRECT If the rotating brush is first moved backward toward the cross-hole, the burrs at the outer edge of the bore are initially pushed in slightly here as well. However, during the subsequent forward movement of the brush, the cutting tips can enter the cross-hole, make contact with the burr root, and cleanly remove the burr. It is essential to also consider the respective machining parameters to ensure a clean deburring.