FLEX-HONE GB31218 Cylinder Hone, 3-1/2 Inch Bore, 180 Grit, Silicon Carbide
- The Brush Research GB31218 Flex-Hone is a standard-duty cylinder honing tool designed for 3-1/2" bore diameter applications. Featuring silicon carbide abrasive in 180 grit, it delivers a medium-fine plateau-style cross-hatch finish ideal for improving oil retention, reducing leakage, and enhancing sealing performance in engine blocks, hydraulic cylinders, pneumatic systems, and similar components.
- Features:
- Bead-style, flexible filament design with self-centering and self-aligning action
- 180 grit silicon carbide abrasive balances peak removal with preservation of oil-retaining valleys (~30–40 µin Ra)
- Non-directional plateau cross-hatch pattern promotes lubrication consistency and reduces fluid leakage
- Robust construction suitable for industrial, automotive, and hydraulic applications
- Specifications:
- Bore Diameter: 3-1/2"
- Abrasive Material: Silicon Carbide
- Grit: 180 (Medium-Fine)
- Abrasive Length: 3-1/2"
- Overall Length: 13.5"
- Stem Diameter: 0.31"
- Recommended Speed: up to 900 RPM
- Typical Surface Finish: 30–40 µin Ra
- Applications: Engine bores, hydraulic cylinders, industrial piping
- The FLEX-HONE GB31218 can also be referred to as 3-1/2" bore hone, GB31218 flex hone, 180 grit cylinder hone, silicon carbide plateau brush, and standard-duty bore finishing tool.
Brush Research Manufacturing’s GB-Series Flex-Hones are trusted tools in automotive, hydraulic, and industrial environments, reliable for delivering consistent plateau finishes in medium bore applications.
Q: What bore diameter is this hone designed for?
A: The GB31218 Flex-Hone is designed specifically for use in 3-1/2" bore diameter cylinders.
Q: What finish quality does the 180 grit provide?
A: The 180 grit delivers a medium-fine plateau finish, typically around 30–40 µin Ra, which aids in seal seating and lubricant retention.
Q: Can this tool be used with a handheld drill?
A: Yes—when using a drill press or handheld drill, maintain speeds up to 900 RPM and use honing oil for lubrication.
Q: What materials is this hone suitable for?
A: It is suitable for cast iron, mild steel, stainless steel, and other ferrous materials commonly used in industrial and hydraulic applications.
Q: What lubricant should be used?
A: A standard oil-based honing lubricant is recommended to protect the abrasive bond and ensure consistent finish quality.
