---
product_id: 390718641
title: "Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2\" (89 mm) Diameter, 120 Grit Size"
brand: "flex-hone"
price: "€ 7.88"
currency: EUR
in_stock: false
url: https://www.desertcart.nl/products/390718641-brush-research-flex-hone-cylinder-hone-gb-series-silicon-carbide
store_origin: NL
region: Netherlands
---

# Self-centering & wear-compensating 3.5" diameter precision fit 120 grit silicon carbide abrasive Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2" (89 mm) Diameter, 120 Grit Size

**Brand:** flex-hone
**Price:** € 7.88
**Availability:** ❌ Out of Stock

## Summary

> 🔧 Hone your edge, own the finish.

## Quick Answers

- **What is this?** Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2" (89 mm) Diameter, 120 Grit Size by flex-hone
- **How much does it cost?** € 7.88 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/390718641-brush-research-flex-hone-cylinder-hone-gb-series-silicon-carbide)

## Best For

- flex-hone enthusiasts

## Why This Product

- Trusted flex-hone brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Seamless CNC & Manual Use:** Optimized for hand use or automated CNC processes, boosting efficiency without compromising quality.
- • **Universal Fit & Flexibility:** Self-aligning design adapts perfectly to bores from 4mm up to 36 inches—no special setup needed.
- • **Durable Silicon Carbide Abrasive:** 120 grit ensures aggressive yet controlled material removal for rapid ring seating and superior surface texture.
- • **Versatile Application Powerhouse:** Ideal for automotive cylinders, firearms, pumps, and more—deburr and finish in one smooth operation.
- • **Effortless Precision Surface Finishing:** Achieve a flawless plateau finish that enhances oil retention and seal longevity.

## Overview

The Brush Research FLEX-HONE GB Series is a 3.5-inch diameter, 120 grit silicon carbide abrasive cylinder hone designed for precision surface finishing and deburring. Its self-centering, self-aligning, and wear-compensating design ensures consistent, high-quality plateau finishes across a wide range of bore sizes, enhancing oil retention, seal performance, and component longevity. Perfect for both manual and CNC applications, this versatile tool is trusted across automotive, firearms, and industrial sectors.

## Description

The Flex-Hone® tool was originally created by Brush Research Manufacturing to deglaze cylinder walls in automotive applications. Brush Research embraced the benefits of a plateau finish and pioneered the concept of plateau honing culminating in the introduction of the Flex-Hone tool in 1972. The Flex-Hone has gained many nicknames over the years and including ball hone, ball style hone, flexihone, dingleberry hone, bead brush, glaze breaker and glaze buster. Flexible honing with the Flex-Hone tool produces an oil holding cross hatch pattern and a true plateau finish free of cut, torn and folded metal. Any type or size of cylinder can benefit from the Flex-Hone®. These abrasive bead style brushes are produced in standard diameters from 4mm to 36 inches. Nine abrasive types are offered including silicon carbide, aluminum oxide, boron carbide and diamond allowing the tool to be tailored to finish any base material. A choice of 11 different grit selections are available for precise control of finish parameters. The elimination of peaks results in rapid ring seating, better oil control, reduced seepage in hydraulic and pneumatic applications and provides better seal performance and longer seal life. Successful applications include firearm chambers, shotgun barrels, musical instruments, combustion chambers, air compressors, pumps, valve bodies, valve guides, brake cylinders, wheel cylinders and the list goes on and on. Flex-Hone® tools are also very effective for deburring cross drilled holes, port radiusing and edge blending. Because of its unique construction, the Flex-Hone is self-centering, self-aligning, and self-compensating for wear so it does not require an elaborate set-up or special training. Deburring can be effectively automated and combined in the machining process to allow a complete cylinder finish in one operation or it can be employed as a secondary operation with equal results.

## Features

- Flexible abrasive cylinder hone for surface finishing and cross hole deburring
- Self-centering, self-aligning, self-compensating for wear
- Use by hand or in CNC equipment
- Order by actual bore size, tool produced oversized
- Sizes from 4mm to 36 inches

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Unit count | 1 count |
| Number of pieces | 1 |
| Recommended uses for product | Deburring, Finishing |
| Manufacturer | Brush Research Mfg. |
| UPC | 843469142832 |
| Item diameter | 3.5 Inches |
| Part number | GB31212 |
| Item Weight | 322 g |
| Item model number | GB31212 |
| Size | 3-1/2\ |
| Style | 120 GRIT |
| Item Package Quantity | 1 |
| Cutting Diameter | 3.5 Inches |
| Measurement System | Inch |
| Grit Rating | 120 |
| Included components | GB 3-1/2" (89MM) 120SC FLEX-HONE |
| Batteries Included? | No |
| Batteries Required? | No |

## Product Details

- **Material:** Silicon Carbide
- **Brand:** Flex-Hone
- **Grit material:** Silicon Carbide
- **Bristle type:** Crimped Wire
- **Grit type:** 120

## Images

![Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2" (89 mm) Diameter, 120 Grit Size - Image 1](https://m.media-amazon.com/images/I/61f9Ueb7-8L.jpg)
![Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2" (89 mm) Diameter, 120 Grit Size - Image 2](https://m.media-amazon.com/images/I/8156ob+ylqL.jpg)
![Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2" (89 mm) Diameter, 120 Grit Size - Image 3](https://m.media-amazon.com/images/I/71LI+vNqxIL.jpg)
![Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2" (89 mm) Diameter, 120 Grit Size - Image 4](https://m.media-amazon.com/images/I/81aPGQTXemL.jpg)
![Brush Research FLEX-HONE Cylinder Hone, GB Series, Silicon Carbide Abrasive, 3-1/2" (89 mm) Diameter, 120 Grit Size - Image 5](https://m.media-amazon.com/images/I/81X4pgWlJtL.jpg)

## Questions & Answers

**Q: Wish one is best for a cylinder wall that is 75mm (2.95 inch) ?**
A: For the cylinder wall bore size of 2.95", the 3" Flex-Hone is the correct choice., Enter this ASIN # B002N3AA2A  in the Amazon search bar for the correct hone.

**Q: Hello, my cylinder bore is 3 1/8" what size tool do i need to purchase thank you.**
A: For a 3.125" bore,  your application will require the 3-1/4" (3.250") diameter Flex-hone. The 3-1/4" will work perfectly in the 3-1/8" bore as the 3-1/4" Flex-hones working range is down to 3.000". Thank you for the inquiry.

**Q: Can i use this to hone out an old cast iron pipe?  it's about 3 3/4" now and i want it at 4" id. thanks**
A: This hone is not coarse enough to remove that much material. It would take forever and the hone would wear out first. You would need a lathe to remove that amount of thickness.

**Q: I see that it says tool is oversized. For a cylinder bore of 3.66, should I be getting the 3.75 or the 3.50 model?**
A: 1I bought a 4.50 and used it on a 3.55 bore with no problem I  didn't hone as much as instruction said for large bore, hatch marks were beautiful  so go bigger and you can use it over a broad area of bores.

## Frequently Bought Together

- Brush Research GB31212 FLEX-HONE®, 3-1/2" (89mm) Diameter, 120 Grit, Silicon Carbide, For Mild Steel, Stainless Steel, Cast Iron and Softer Ferrous Materials
- Brush Research FHQ FLEX-HONE® Oil, Specially Formulated Honing Oil, 1 Quart Bottle (32 fl oz)
- Permatex 81950 Ultra Slick Engine Assembly Lube, 4 oz. , Red

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*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-02-18*