3-1/2" FLEX HONE 320 GRIT - Brush Research

The Brush Research GBD31232 3-1/2" FLEX-HONE is a professional-grade abrasive tool engineered to deliver a consistent, controlled plateau finish in various cylinder bores. Designed for demanding automotive, diesel, and industrial applications, this flexible hone effectively conditions surfaces, deburrs, and deglazes in a single operation, without altering the bore's original size or geometry, ensuring reliable and repeatable results for optimal engine and hydraulic system performance.

Key Features

• Controlled Plateau Finish: Utilizes 320 grit silicon carbide abrasive to create an ideal plateau finish, crucial for proper ring seating, enhanced lubrication retention, and reduced friction, which collectively improve oil film stability and sealing performance within cylinders.
• Self-Centering Flexible Design: The unique construction allows the abrasive globules to float, ensuring the honing head precisely conforms to the bore shape, providing even pressure and contact to prevent issues like taper, out-of-round conditions, or edge gouging.
• Simultaneous Conditioning and Deburring: Efficiently removes torn and folded metal, burrs, and micro-fractures while refining the bore surface, even in cross-drilled and ported applications.
• Non-Directional Cross-Hatch Pattern: Generates a uniform surface profile that significantly enhances oil film stability and sealing, contributing to increased compression, improved power, and reduced oil consumption.
• Durable, Professional Construction: Built in the U.S. for sustained professional use, this heavy-duty FLEX-HONE features a 13.5" overall length and a 5" abrasive section, suitable for hand drills or low-RPM production equipment (900–1200 RPM).

Applications

This 3-1/2" FLEX-HONE is ideal for the final finishing and deglazing of engine cylinders in automotive, marine, and stationary diesel engines within its specified 3.050"–3.550" (77–90 mm) bore range. It is also highly effective for improving the performance of hydraulic and pneumatic cylinders, brake caliper bores, valve guides, piston pin bores, and camshaft/crankshaft oil passages where critical oil flow and sealing are required. Suitable for use on mild steel, stainless steel, cast iron, and other softer ferrous materials after boring or reaming operations.

Specifications

• Manufacturer: Brush Research
• Model: GBD31232
• Nominal Diameter: 3-1/2" (89 mm)
• Bore Range: 3.050"–3.550" (77–90 mm)
• Grit: 320 Silicon Carbide (extra fine)
• Overall Length: 13.5"
• Hone Length: 5"
• Stem Diameter: 0.31"
• Max RPM: 900–1200
• Weight: 2 lb
• Material Compatibility: Mild steel, stainless steel, cast iron, softer ferrous alloys