Los Angeles—Brush Research Manufacturing is introducing its Flex-Hone Tool to manufacturers, rebuilders, and service shops for use on brake system rotors. The honing tool produces a final finish that eliminates braking noise and extends brake service life. The same tool may also be used on flywheels to remove torn, cut, and folded metal fragments.
The Flex-Hone is a versatile tool used throughout industry where metal machining is involved. This ball-style hone is recognizable by the abrasive globules, sometimes called “dingle berries,” mounted to nylon filaments. Known widely as a tool used for de-burring, plateau honing, and deglazing, this is an inexpensive yet sophisticated device. A precision-quality flexible hone not only de-burrs bored metal, but can easily remove even microscopic metal shards and fragments.
A few years ago, when Miller Industrial Products got an order to make brake drums for Cadillac stretch limousines, they knew from the beginning that quality and performance were critical issues. The big limos are the heavyweights of passenger cars, and required the support of much beefier axles.
“These stretch limos were not only much larger than standard models in overall size, but also featured bullet-proof windows and doors plus a heavy-duty undercarriage,” said owner Bill Miller. “Therefore, the brake system required the size of brake drums used on trucks. But at the same time, since these were ultra-luxury vehicles, the brakes had to be quiet—and that was a new challenge.”
Miller, a specialist in brake systems, explained that drum-brake systems previously had used asbestos-lined shoes that were inherently much quieter than new ones. Since asbestos has been outlawed, new brakes—whether drum or disk styles—tended to be noisy if the hard metal finishes were not finished perfectly smooth.
“That is more difficult to accomplish than many people thought at the time,” Miller said. “Any irregularities in the surface of the drums would cause a squeal, hum, or slapping noise that was unacceptable to the OEM, which was very understandable.”
Miller says what was needed was a unique honing process to give the brake drums an ultra-smooth finish. To accomplish this, he turned to Brush Research Manufacturing (BRM) in Los Angeles, a manufacturer of honing tools, deburring brushes and other abrasive technology tools.
“BRM has a history of solving finishing problems, and makes a ball-style honing tool, the Flex-Hone, that allows you to achieve a very smooth finish,” said Miller. “So we looked at this flexible hone and developed a special process to machine the brake drums and then hone them in such a way that they were completely silent. And it worked so well that the engineers at Cadillac were amazed.”
The Flex-Hone is a lightweight and portable tool, making it adaptable to many different processes and setups. The tool can be chucked easily into a variable-speed electric drill motor or low-speed air drill.
