Flexible Hones – Tool Diameter, Speed, and Stroke Rate

The Flex-Hone® Resource Guide explains how to select the right flexible honing tool for your deburring or surface finishing application. Available in 8 different abrasive types and 11 grit options, BRM cylinder hones improve internal surface finish and can remove cut, torn, and folded metal (burrs). Self-centering and self-aligning to the bore, BRM ball hones create a substantially flat or plateau finish that promotes optimum lubrication and reduces wear.

Tool Selection and Flex-Hone® Diameter

As the Flex-Hone® Resource Guide explains, Flex-Hone® users should select and use cylinder honing tools based on parameters such as tool diameter, stroke length, and revolutions per minute (RPMs). Tool diameter, an especially important specification, is determined by the nominal bore size in which the flexible hone will operate. As a rule, ball hones are produced and used in an oversize condition.

When selecting a cylinder hone then, order a honing tool with a diameter that’s larger than the bore you plan to surface-finish. The degree of oversize creates a soft cutting action that imparts a non-directional or cross-hatched pattern. For example, if the nominal bore of an engine cylinder is 1.093”, order a BRM ball hone with a diameter of 1-1/8”.

Flexible hones are produced in diameters from 4-mm to 36” and work with any type or size cylinder. So whether you need small-diameter flexible hones, standard heavy-duty brush tools, or super heavy-duty large-diameter ball hones, BRM offers Flex-Hone® tools to meet your surface finishing and burr removal challenges. In addition to tool diameter, however, you’ll need to consider speed and stroke rate.

RPMs, Stroke Rate, and Lubrication

As the Flex-Hone® Resource Guide explains, BRM flexible hones are low RPM tools. This free technical guide provides general speed ranges, but recommends machine trials to verify parameters. As a rule, tool diameter and application determine the optimum RPMs. Smaller hones require faster speeds, and larger hones require slower speeds.

Like RPMs, stroke rate is also a function of Flex-Hone® diameter. Along with stroke length, cross-hatch angle (if any) is also important to consider, especially since high cross-hatch angles require faster stroke rates. Larger-diameter cylinder honing tools might feed as slow as 100 to 120 inches per minute (IPM), but smaller-diameter cylinder hones with high cross-hatch angles might require feed up to 250 IPM.

Always use BRM flexible hones with a lubricant, preferably Flex-Hone® oil. Other acceptable fluids include water-soluble oils, mineral oils, motor oils, and cutting and tapping fluids. Never use solvents, as they tend to degrade the adhesive bonds between the ball hone’s abrasive globules and flexible nylon abrasive filaments.

Always lubricate flexible honing tools generously to prevent tool loading and ensure the exposure of fresh cutting particles. For complete information about how to select and use BRM cylinder hones, download the free, full-color Flex-Hone® Resource Guide today.