Custom End Brushes

It is a small bundle of fill, usually 10–32 mm across, held in a cup or ferrule at the end of a steel shank. As it turns, the ends of the filament do the work. That makes it the most concentrated brush there is: the whole tuft acts on a spot the size of its own diameter.

A cup brush spreads its contact over a wide face, and a wheel brush works along its rim. An end brush is the one to choose when the feature is small and recessed: the inside of a counterbore, the floor of a pocket, a spot weld, the entry of a drilled hole, a corner inside a mold.

In our range, end brushes are shank-mounted with brass, carbon steel or 316 stainless wire, 11–32 mm across. Wool brushes cover soft dusting, polishing and controlled application work on leather and similar surfaces. Both start at 500 pieces per design.

• Brass wire: softer metal contact for threads, recesses and non-ferrous parts, and where marking or sparks must be limited.
• Stainless steel wire: for stainless and aluminum parts and for weld detail on stainless, so no carbon steel is left to rust.
• Carbon steel wire: the hardest cutting, for ferrous parts where traces of carbon steel are acceptable.
• Abrasive nylon: grit-bearing filament for a defined, even cut on edges and hole entries.
• Wool and soft fill: for polishing, dusting and applying wax, dye or adhesive.

From the feature. The brush diameter should be a little smaller than the hole or pocket it has to enter, so it reaches the floor without the shank or ferrule rubbing the wall. The fill length sets the flex: short fill is stiff and aggressive, long fill reaches further and follows shape. The shank has to fit the collet or chuck, commonly 6 mm or 1/4 inch on die grinders, and be long enough to reach the feature with clearance for the tool.

Bring it to the work square, with the tips leading, and use light pressure; pushing hard folds the wire over and wears the sides. Keep the tool within the brush’s maximum speed. Move it in small circles or along the edge rather than holding it on one spot, which overheats both the brush and the part. For deburring a hole entry, run the brush into the hole a short way and back out.

Wear eye protection and gloves; loose wires fly at speed. Run a new brush for a moment pointed away from you before it touches the work. Never exceed the brush’s rated speed. Check that the shank is fully seated in the collet. Retire a brush whose wires have bent flat or whose tuft has started to open.

• The feature: hole or pocket diameter and depth, or a drawing of the area.
• The part material, the deposit or burr, and the finish you need.
• Brush diameter, fill and fill length, if you know them.
• The tool, its collet or chuck size, and its speed.
• Your brand and packaging, and the quantity per design.