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BRM's Flexible Honing, Surface Finishing, and Deburring Blog

BRM's Flexible Honing, Surface Finishing, and Deburring Blog is the place for conversation and discussion about how to solve difficult finishing problems. For over 50 years, Brush Research Manufacturing (BRM) has helped customers use brushing technology to clean, rebuild, and resurface components ranging from engine cylinders to brake rotors to flywheels to firearms. BRM's Blog on CR4 provides real-world examples of how flex hones and wire brushes work. It also evaluates related technologies and invites questions from the community.

Brake Rotor Finishing for the Automotive Aftermarket

Posted October 20, 2014 1:45 PM by Brush Research

Aftermarket disc brake rotors include high-quality auto parts that are made from new or recycled metals and machined to tight tolerances. By maintaining the right spacing between surfaces, these aftermarket brake parts ensure proper cooling and promote easy installation. Machine-balanced for trueness, many aftermarket rotors also feature an electroplated hub to prevent rust and corrosion.

For brake mechanics and aftermarket rotor manufacturers alike, it's important for brake rotor surfaces to have a smooth surface finish. Most premium brake rotors meet roughness average (RA) requirements specified by the original equipment manufacturer (OEM). Economy brake rotors may have a rougher surface finish, but are usually ready to install right out-of-the-box.

Without the right rotor surface finish, however, disc brakes may speak or squeal. Related brake problems include poor pad seating and break-in, increased friction and wear, and buildups of brake pad glaze and surface corrosion. Fortunately, Brush Research Manufacturing (BRM) supplies a surface finishing tool that, as this YouTube video shows, is ideal for surface finishing new and re-turned rotors.

Flexible Honing for Rotors

The Flex-Hone for Rotors is a reliable, cost-effective, automotive brush tool for do-it-yourself mechanics (DIY), professional brake specialists, and aftermarket brake rotor manufacturers. Suitable for mounting in a handheld electric drill or production equipment, the Flex-Hone for Rotors features long-lasting abrasive globules that are permanently laminated to flexible nylon filaments.

BRM's brake honing tools come in coarse, medium, and fine grits. Coarse-grit rotor hones remove heavy buildup and corrosion during brake jobs. Medium-grit brake tools also remove layers of pad material, but impart a smoother surface finish. Fine-grit flexible hones impart the finest rotor finish of all, and may be used after coarse-grit and then medium-grit tools.

Named an Undercar Digest Magazine "Top Ten Tool" eight years in a row, the Flex-Hone for Rotors was featured in the August 2014 edition DSPORT magazine. In an article called Glaze is for Donuts: Do-It-Yourself Disc Brake Resurfacing, automotive writer Jun Chen explained why BRM's brake rotor hones are the right choice for disc brake rotor resurfacing.

From the Race Track to the AAPEX Show

First, DSPORT removed four used rotors from a race car. Equipped with a power drill and a coarse-grit flexible honing tool, a mechanic then removed the transfer layer from each rotor face. The brake tech then switched to a medium-grit tool, and finally to a fine-grit Flex-Hone for Rotors. Because the BRM brake hone is self-leveling and applies uniform pressure, keeping it square and flat was an easy task.

As the Flex-Hone for Rotors brochure explains, BRM's rotor honing tool should be held securely in a collet, chuck, or similar holding device. Use light, uniform pressure rather than excessive dwell time. To produce the desired surface finish, use the brushing tool for approximately 10 - 15 seconds clockwise and 5 - 10 seconds counterclockwise. Do not overhead by dwelling for longer periods of time.

Do your tradeshow plans include a visit to the Automotive Aftermarket Products Expo (AAPEX) next month? Then visit BRM in Booth #1152 at the Sands Expo in Las Vegas and see the Flex-Hone for Rotors for yourself. Contact BRM to arrange a meeting in advance, and learn more about Brush Research Manufacturing's full line of automotive surface finishing solutions, as shown in this AAPEX video.

Author's Note: This CR4 Blog Entry originally appeared in BRM's Flex-Hone Blog.

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Surface Finishing for the Automotive Aftermarket

Posted October 13, 2014 3:20 PM by Brush Research

AAPEX 2014 is where the automotive aftermarket builds business relationships and sources auto parts, tools, and equipment. From November 3 to 6, 2014, domestic and international suppliers will meet with warehouse distributors, retailers, service providers, manufacturers' reps, and buyers at the Sands Expo in Las Vegas, Nevada. For the 130,000 automotive professionals in the Exhibit Hall, the Automotive Aftermarket Products Expo (AAPEX) is the heart of the $395-billion global motor vehicle aftermarket.

For AAPEX participants in search of surface finishing solutions, the Brush Research Manufacturing (BRM) booth is the place to find industry-leading tools and technologies. Visit BRM in AAPEX Booth #1152 and see Flex-Hone tools, NamPower technology, and diesel and automotive brushes. Distributor programs are available for jobbers and stocking warehouse distributors, and export inquiries are welcome.

Flex-Hone Tools for Cylinder Surface Finishing and Brake Jobs

BRM Flex-Hone tools set the industry standard for the inner diameter (ID) finishing of engine and brake cylinders, cam bearing and crank bores, and valve guides and bodies. Additional automotive aftermarket applications for flexible cylinder hones include connecting rods, piston pin bores, engine liners, cross-holes, and specific surface finishes.

With their distinctive abrasive globules, BRM ball hones also remove burrs and deglaze cylinder walls. Self-centering, self-aligning to the bore, and self-centering for wear, flexible cylinder honing tools are easy-to-use and require no special training. The engine hone's metal stem mounts in a handheld power tool such as an electric drill, or in production machinery such as a CNC machine center.

BRM's glaze breaker hones impart a cross-hatched pattern of oil-retaining grooves for optimum lubrication and piston ring seating. Flex-Hone technology is also used to finish automotive and motorcycle disc brake rotors, automotive fly wheels, and clutch plates. The Flex-Hone for Rotors imparts a non-directional pattern that's ideal for both new and re-turned rotors.

NamPower Technology for Engine Block Tops and Auto Parts

BRM NamPower technology is a family of high-performance nylon abrasive brushing tools for outer diameter (OD) applications such as finishing the tops of engine blocks. Powerful and reliable, these abrasive nylon brushes conform closely to part contours and remove burrs consistently. Sharp, new abrasive grains constantly come into contact with the auto part surface, exposing fresh cutting particles.

The NamPower family of products includes abrasive disc brushes, composite hub wheels, abrasive hex-drive tools, and accessories such as lightweight tool holders that dampen vibrations and support flow-through cooling. With their well-balanced construction, NamPower brush tools are ideal for use with automated machinery. In addition to engine block finishing, NamPower applications include deburring and finishing metal and plastic automotive parts.

Automotive Brushes for Engine Maintenance and Parts Cleaning

Brush Research also offers automotive and diesel brushes for cleaning, finishing, and polishing auto parts and engines. Applications for automotive brushes include deburring cast aluminum engine heads, surface conditioning manifolds, and polishing holes on machined parts. Diesel brushes include general diesel tools as well as specialty brushes for Cummins Group, Caterpillar, and Detroit Diesel engines. Valve guide, oil line and gallery, and display brushes are also available.

As a full-line brush manufacturer with a global distribution network, BRM also supplies parts wash brushes with a non-slip grip, heavy-duty construction, and penetrating tip. Guaranteed not to mushroom, these brush tools feature injection-molded polypropylene handles and synthetic filaments for resistance to solvent cleaners. All metal parts are either stainless steel or brass for corrosion resistance, and all tube fittings are manufactured for use with popular recirculating parts washers.

Automotive Surface Finishing Starts Here

Do your tradeshow plans include a visit to the Automotive Aftermarket Products Expo (AAPEX) in Las Vegas, Nevada next month? From November 3 to 6, visit BRM at AAPEX in Booth #1152 at the Sands Expo. To arrange a meeting in advance, contact us today. Even if you can't make the show, check out BRM's latest video: Surface Finishing for the Automotive Aftermarket - BRM at AAPEX 2014 (Booth 1152)

Author's Note: This CR4 blog entry originally appeared in the BRM Flex-Hone blog.

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How Cylinder Honing Improves Piston Ring Seating

Posted October 06, 2014 1:34 PM by Brush Research

Piston rings are engine parts that seal the combustion chamber, transfer heat from the piston to the cylinder wall, and help regulate oil consumption. During normal engine operation, only small amounts of exhaust gases and unburned fuel escape the piston rings and enter the crankcase. If there are gaps between the piston rings and the cylinder walls, however, too much "blow-by" can enter the crankcase and overwhelm its ventilation system. The results range from power loss to engine damage.

"The piston ring is sort of the poor stepchild of the high-performance engine," explains Keith Jones of Total Seal, a Phoenix-based manufacturer of piston ring sets for street and racing engines. "They get blamed for just about everything." Without the proper fit between the piston ring and the cylinder bore, however, compression blow-by and oil leakage can sideline the kinds of car used in IRL, NASCAR, and World of Outlaws events.

High-Performance Surface Preparation

As an article in the October 2014 issue of Performance and Hotrod Business magazine explains, Flex-Hone tools from Brush Research Manufacturing (BRM) can help increase piston ring performance. In "Rings True", part of the publication's Precision Engine section, automotive writer Ed Sullivan describes how BRM's flexible hones "allow for the fine-tuning of cylinder bores", even in engine blocks made of harder metals that can make piston ring break-in challenging.

BRM Flex-Hone tools feature abrasive globules that are permanently laminated to flexible nylon filaments, and a sturdy metal stem that mounts in handheld power tools or CNC machinery. Self-centering, self-aligning to the bore, and self-compensating for wear, flexible cylinder hones are ideal for deglazing the walls of cylinders that are not out-of-round, and for improving the surface finish of bores that have been honed to size already.

Flexible honing tools aren't designed for heavy-duty material removal, however, nor should they be used for initial honing, cylinder resizing, or geometry correction (i.e., out-of-round bores). Instead, use BRM Flex-Hone tools to impart a plateau finish that optimizes engine lubrication for reduced friction and wear. The crosshatching that flexible honing imparts provides a uniform series of grooves for excellent oil retention, and a superior surface finish that supports piston ring seating and sealing.

Engine Hones and Cylinder Wall Surface Finishing

BRM's engine hones are available in 11 different abrasive types and 8 grit sizes. The Flex-Hone Resource Guide explains how to select and use ball hones, as Flex-Hone tools are also known. Industry experts such as Keith Jones of Total Seal also provide insights. As Jones told Performance and Hotrod Business magazine, "We recommend this type of hone because it works very well, is easy to use with a hand-held drill motor, and is really foolproof for someone who is not an experienced machinist."

Michael Miller, BRM's Vice President of Global Sales, adds that Total Seal "does its homework" when it comes to choosing specific Flex-Hone tools. The levigated alumina super-fine abrasive that the engine parts maker recommends "works best for their piston rings in harder engine block materials." Members of the automotive aftermarket and performance racing industries are encouraged to contact BRM with questions about flexible cylinder honing. "We provide this type of support all the time", Miller explains.

Author's Note: This CR4 blog entry originally appeared in BRM's Flex-Hone Blog.

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Diamond Hones for Surface Finishing Hard Materials

Posted September 29, 2014 1:01 PM by Brush Research

Diamond hones are designed for the inner diameter (ID) surface finishing of parts made of hard materials. Examples include carbide wear rings and ceramic cylinders. BRM's Diamond Flex-Hone tools are also used to deburr, edge blend, and surface finish parts made of high nickel stainless steels, hardened tool steels, proprietary metals such as Inconel 718 and Waspalloy, and titanium and aluminum alloys used in jet engines.

Diamond Flex-Hone Video

As this new BRM video shows, BRM's diamond honing tools feature resin-bonded diamond crystals with rapid cut-rates and self-sharpening edges. The flexible cylinder hone's nickel-coated diamond abrasive promotes heat dissipation and bond retention for longer tool life. By conforming closely to the contours of machined components, the Diamond Flex-Hone removes burrs consistently, helping to prevent part misalignments and achieve tight tolerances in industries where failure is not an option.

BRM's flexible diamond hones also blend edges and eliminate stress risers to promote smooth, radiused edge transitions. By improving hole quality and removing microburrs, flexible diamond hones help to avoid stress corrosion cracks and damage to the part. Like all Flex-Hone tools, the Diamond Flex-Hone is self-centering, self-compensating for wear, and self-aligning to the bore. By improving surface quality without heavy-duty material removal, the tool leaves the base material undisturbed.

Product Specifications and Benefits

As this brochure explains, BRM supplies Diamond Flex-Hone tools in stocked sizes ranging from 4-mm (0.157-in) to 20-mm (0.787-in), and by special order from 22-mm (0.875-in) to 38-mm (1.5-in). To produce a soft cutting action, each flexible diamond hone is supplied and used in an oversized condition. This produces the appropriate amount of pressure against the cylinder wall, allowing the Diamond Flex-Hone to remove burrs, blend edges, and improve surface finish.

Diamond Flex-Hone tools are available in three mesh sizes: 170/200, 800, and 2500. Measured by passing the diamond abrasive through a stack of sieves or screens, mesh is a size distribution that's related to grit. If a part's surface requires significant improvement, start with a lower-grit Diamond Flex-Hone and then use one or more higher-grit tools. That's what a manufacturer of carbide wear rings did to lower average surface roughness (Ra) from 0.7 to 0.05 µm and produce a near-mirror finish.

Automated Operations and Leading Applications

Diamond Flex-Hone tools are suitable for both off-line and in-machine operations. Built with a rigid, twisted wire metal stem, these surface finishing and deburring tools mount easily in handheld electric drills. BRM's flexible diamond hones are also ideal for production equipment such as CNC machining centers. Suitable for use with most any machine spindle, Diamond Flex-Hone tools help to reduce labor costs, optimize machine cycle times, and promote surface finish uniformity.

Today, Diamond Flex-Hone tools are used in aerospace and medical applications. Examples include through-hole edge rounding in aircraft engine components, chamfer blending on rotating engine parts, and removing stress risers and polishing holes for landing gear equipment. Flexible diamond abrasive honing tools are also used to surface finish helicopter rotor drive shafts and deburr the bearing surfaces of hydraulic swivel components. To learn more, download the Future in Finishing white paper.

Author's Note: This CR4 blog entry originally appeared in BRM's Flex-Hone Blog.

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How to Select Abrasives and Grits for Flexible Honing Tools

Posted September 22, 2014 12:09 PM by Brush Research

Flexible cylinder honing is a low-pressure, low-temperature abrading process that removes burrs and improves surface finish at the same time. Unlike rigid hones, which have only two or three stones, flexible cylinder hones have hundreds of cutting points for a full 360° of cutting action. As the abrasive globules on a flexible honing tool wear, fresh cutting particles are continuously exposed.

Brush Research Manufacturing (BRM) supplies Flex-Hone tools in 10 different abrasive types and 11 different grit sizes. Eight of the abrasives are standard, and two are available by special order. The base material of the workpiece determines which abrasive to choose. The amount of work to perform and the degree of surface improvement that's required determines which grit size to select.

Depending upon the application, Flex-Hone tools in several different grits may be required. If a surface requires significant improvement, start with a lower-grit Flex-Hone and then use one or more higher-grit tools until the final finish is achieved. The use of a fine-grit deburring tool on a coarse starting finish is less effective than a coarse-grit tool followed by a fine-grit tool.

Standard Abrasive Types

Standard Flex-Hone tools are available in the following abrasive types: silicon carbide, aluminum oxide, zirconia alumina (No. 1525 and No. 1549), boron carbide, tungsten carbide, levigated alumina, and diamond. BRM ball hones with cubic boron nitride or ceramic abrasive are available by special order only. The Flex-Hone Resource Guide lists the available grit sizes for each standard abrasive type.

Silicon carbide (SC) is used with cast iron, mild steel, or stainless steel. For deburring and surface finishing aluminum, brass, bronze, or softer metals, choose aluminum oxide (AO) abrasive. 240-AO Flex-Hone tools are recommended for Nikasil cylinders. An extremely hard material that's used to line the surfaces of engine components, Nikasil reduces friction and wear, especially in aluminum engines.

Zirconia alumina (ZA) abrasive provides longer tool life than silicon carbide, but is suitable for many of the same materials. Z-grain No. 1525 consist of 25% zirconia and 75% alumina. Z-grain No. 1549 consist of 40% zirconia and 60% alumina. Both types of ZA Flex-Hone tools are designed for use with cast iron, low carbon steels, medium carbon steels, and stainless steel.

Boron carbide (BC) abrasive is used with medium carbon steels, high carbon steels, heat-treated steels to 50 Rc, and titanium. Tungsten carbide (WC) is for high carbon steel alloys and more exotic space age alloys. Choose either 100% WC Flex-Hone tools, or BRM flexible cylinder hones with a 50/50 blend. Levigated alumina is available in extra fine grit only, and ideal for a final polish on many materials.

Diamond Flex-Hone Tools and Specialty Abrasives

Diamond Flex-Hone tools are recommended for deburring, surface finishing, and edge-blending carbide, ceramic, hardened tool steels, heat-treated steels, and other hard materials. Made with nickel-coated abrasive, these diamond honing tools offer excellent heat dissipation and bond retention. As the Diamond Flex-Hone brochure explains, applications include aerospace components and medical parts.

Brush Research Manufacturing (BRM) also supplies Flex-Hone tools with cubic born nitride (CBN) CBN and ceramic abrasive. Available by special order only, these flexible honing tools combine the proven benefits of Flex-Hone technology with specialty abrasives for demanding applications. To learn more about BRM's full-line of surface finishing solutions, contact us today.

This CR4 blog entry originally appeared in BRM's Flex-Hone Blog, where you'll find more information about surface finishing and deburring solutions.

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How Manufacturers Use Flexible Honing Tools

Posted September 15, 2014 2:07 PM by Brush Research

Manufacturers are using flexible honing tools to automate surface finishing and deburring operations. By removing burrs and improving surface finish at the same time, they're improving part quality and consistency while increasing efficiency and boosting productivity.

ID Surface Finishing and Deburring

BRM Flex-Hone tools are the industry standard for inner diameter (ID) surface finishing and deburring. Known also as ball hones, these flexible cylinder hones feature abrasive globules that are permanently laminated to flexible nylon filaments. Self-centering, self-aligning to the bore, and self-compensating for wear, these deburring tools remove cut, torn, and folded metal while imparting a plateau finish with oil-retaining grooves for optimum lubrication.

Flex-Hone tools are also built with a stiff, double-wire metal stem for easy mounting. Manufacturers can use these surface finishing and deburring tools during machine tool applications (on-line), or during secondary operations (off-line). Regardless of how they're used, flexible cylinder hones always require the use of a lubricant. Choose a high-quality honing oil (such as Flex-Hone oil), or other good-quality lubrication (such as machine oils). Lubricate the ball hone generously, and never use solvents.

On-Line and Off-Line Operations

For on-line operations, flexible honing tools mount in most machine spindles. Examples include drill presses, lathes, and milling machines as well as robotic cells, transfer lines, and CNC equipment. With CNC machinery, a Jacobs-style chuck or CAT 40 collet is recommended. The Flex-Hone In-Machine Setup video shows how BRM's cylinder honing tools are mounted and used. For off-line use, flexible hones can be used with a handheld power tool such as an electric drill.

As the Flex-Hone Resource Guide explains, BRM's surface finish improvement and burr removal tools come in 10 different abrasive types, 11 grit sizes, and in standard diameters ranging from 4-mm to 36". The base material determines which abrasive to select. The amount of work to perform and the degree of surface improvement to achieve govern the grit selection. Available grit sizes vary by abrasive type, and some options are available by special order.

Diamond Hones

Diamond Flex-Hone tools feature diamond abrasive for finishing carbide wear parts, ceramic cylinders, chromed and plated bores, electrical discharge machining (EDM) layers, and guide and drill bushings. Precision-engineered for rapid cut rates, BRM diamond hones also offer excellent heat dissipation. The self-sharpening, resin-bonded crystals in each diamond honing tool are ideal for hard materials such as heat-treated steel, titanium, stainless steel, and space age alloys.

Industries and Applications

Flex-Hone tools that use other abrasives (such as AO and SC) are used to deburr and improve the surface finish of manufactured parts such as engine cylinders and pneumatic cylinders. In fluid power applications, flexible cylinder hones are ideal for hydraulic cylinders, ram cylinders, valve bodies, and valve guides. Flex-Hone tools are used with the valve housings and pump housings on industrial enclosures, too. General industry applications include surface preparation and decontamination.

BRM Flex-Hone tools are also used in industries and applications such as aerospace, automotive, earth moving equipment, marine, oil and gas, aluminum extrusion, brass instruments, firearms, fluid power, hydraulics, and military/defense. For more information, visit the applications page on the BRM website. The Brush Research Manufacturing YouTube channel is also a great source of information, and includes a Flex-Hone Tools Application video that describes the BRM ball hone's versatility and benefits.

Author's Note: This CR4 blog entry originally appeared in BRM's Flex-Hone Blog.

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