---
product_id: 97953475
title: "Brush Research BC78400AO Flex-Hone®, 7/8\" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials"
brand: "flex-hone"
price: "¥15962"
currency: JPY
in_stock: true
reviews_count: 9
category: "Flex Hone"
url: https://www.desertcart.jp/products/97953475-brush-research-bc78400ao-flex-hone-7-8-22-2mm-diameter
store_origin: JP
region: Japan
---

# 0.875" diameter fits 0.788"-0.875" bores 400 grit Aluminum Oxide for precision finish Made in USA for trusted quality Brush Research BC78400AO Flex-Hone®, 7/8" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials

**Brand:** flex-hone
**Price:** ¥15962
**Availability:** ✅ In Stock

## Summary

> 🔧 Elevate your cylinder prep game with precision and ease!

## Quick Answers

- **What is this?** Brush Research BC78400AO Flex-Hone®, 7/8" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials by flex-hone
- **How much does it cost?** ¥15962 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/97953475-brush-research-bc78400ao-flex-hone-7-8-22-2mm-diameter)

## 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

- • **Durable & User-Friendly:** Forgiving ball fingers resist damage and reset easily, perfect for both pros and home mechanics.
- • **Precision Crosshatch Finish:** Achieve optimal oil retention and rapid ring seating with a 400 grit plateau honing surface.
- • **Self-Centering & Self-Aligning:** Oversized design ensures perfect alignment and consistent pressure without special setup.
- • **Versatile Material Compatibility:** Engineered for aluminum, brass, bronze, and softer non-ferrous metals—ideal for hydraulic, pneumatic, and engine cylinders.
- • **Dual-Action Deburring & Finishing:** Simultaneously deburr crossholes and finish surfaces in one efficient operation.

## Overview

The Brush Research BC78400AO Flex-Hone® is a 7/8" diameter, 400 grit aluminum oxide honing tool designed for soft non-ferrous materials like aluminum, brass, and bronze. Proudly made in the USA, its oversized, self-centering design delivers a consistent crosshatch finish that enhances oil retention and seal life. Ideal for automotive, hydraulic, and pneumatic cylinder refinishing, it also deburrs crossholes efficiently, making it a must-have for professional and DIY engine rebuilds.

## 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, Z-Grain, Leviagted Alumina, CBN 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.

Review: Mandatory tool for proper Nickasil cylinder prep when replacing pistons and rings - I decided to rebuild my snowmobile motors as preventative maintenance, and was replacing pistons and rings. The piston suppliers all recommend cylinder prep with these type of ball hones. I bought two hones, one for my 500 cc sleds and one for my 800 cc sled. There are many grits and compounds available, but for Nickasil cylinders these 320 grit Aluminum Oxide versions are recommended. They worked perfectly for de-glazing and refreshing the crosshatch to help in proper cylinder oiling and piston and ring break-in. Choose the ball hone size you need based on the actual cylinder bore diameter. If you buy the hone that matches your diameter it is actually slightly oversized to create just the right amount of pressure to the cylinder wall for effective honing. Using these ball hones takes a bit of technique, but in a home shop environment I found doing the honing in a 5 gallon bucket worked to contain the lube oil from flinging all over the shop, I also made a short spacer to place under the bottom of the cylinder edge inside the bucket to lift the cylinder just enough off the bottom to allow the hone to effectively reach through the cylinder with a full stroke, but not protrude too far through and allow the balls to wrap the lip and bind. Holding the cylinder solid in the bucket also helped to keep the hone centered within the cylinder as cocking it at any angle while holding the cylinder by hand tended to end up with the hone hooking a port or the lip and stopping the process (my first attempts were a bit of a learning curve). Once I figured out how to hold the cylinder and limit the travel properly the remaining cylinders were easy to complete. If you do bind the hone and twist some of the ball fingers, they are very forgiving, and easy to re-set the fingers, straighten them out, and continue on, being more careful about your process. These hones should last forever if you're only using them periodically in a home shop. Using them per the included instructions left a beautiful surface with correctly angled cross-hatch, and made for a perfect top-end rebuild. These are far better than the old spring loaded stone-hones of old, especially for nickasil. These also have a far less likelihood of catching a port if you keep it centered. And if it does catch one due to your (My) own mistakes, it will simply bend around itself but not cause any damage, unlike the potential damage that could be caused if a stone catches a port with the old style hones. Highly recommend this product and the seller.
Review: LS1 valve guide hone - Worked great for LS1 head valve guides when I had to replace a broken one. Easy to use and the correct size. Priced right for what it does.

## Features

- [QUALITY]-Proudly Made in the USA. Quality and consistency you can count on made from the inventors and makers of the tool.
- [DESIGN]-The FLEX-HONE is intentionally manufactured oversized. This engineered oversize creates the optimal amount of pressure inside the cylinder wall allowing the tool to be self-centering, self-aligning and self-compensating for wear and easy use.
- [FINISHING BENEFITS]-Offered in a wide variety of grits to achieve specific finishing tolerances as well as a beautiful crosshatch finish. Ideal for rebuilding hydraulic and pneumatic cylinders, engine and brake cylinders, valve guides, pumps, compressors and more.
- [CROSSHOLE DEBURRING]-Accomplish finishing and deburring simultaneously in a single setup. Can be used in virtually any rotating spindle from a hand drill, drill press or CNC equipment.
- [400 GRIT ALUMINUM OXIDE ABRASIVE]-Excellent on Aluminum, Brass, Bronze, and softer non-ferrous materials. 240 AO is commonly used for deglazing Nikasil cylinders. Typically achieves a finish of 10 - 20 Microinch (.3 - .6 Micrometer).
- [WHAT'S INCLUDED]-1 Each of a BC Standard Duty FLEX-HONE: 0.875" (22.2mm) Bore Diameter, 3" Abrasive Part Length, 0.228" Shank Diameter, 8" Overall Length. For Use on Bore Diameters Between 0.788"-0.875". PLEASE NOTE: ORDER BY BORE SIZE.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B002T01VTI |
| Best Sellers Rank | #27,966 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #6 in Flex Hones |
| Date First Available | July 7, 2011 |
| Is Discontinued By Manufacturer | No |
| Item Diameter | 0.88 Inches |
| Item Weight | 2.08 ounces |
| Item model number | BC78400AO |
| Manufacturer | Brush Research Manufacturing |
| Number of Pieces | 1 |
| UPC | 843469130907 |
| Unit Count | 1.0 Count |

## Product Details

- **Brand:** Flex-Hone
- **Bristle Type:** Abrasive Globule Bonded To Flexible Nylon Filament
- **Grit Material:** Aluminum Oxide
- **Grit Type:** 400 Grit
- **Material:** Aluminum Oxide

## Images

![Brush Research BC78400AO Flex-Hone®, 7/8" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials - Image 1](https://m.media-amazon.com/images/I/21rNPJAmmwL.jpg)
![Brush Research BC78400AO Flex-Hone®, 7/8" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials - Image 2](https://m.media-amazon.com/images/I/41I3V5gzetL.jpg)
![Brush Research BC78400AO Flex-Hone®, 7/8" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials - Image 3](https://m.media-amazon.com/images/I/41itOYlPQwL.jpg)
![Brush Research BC78400AO Flex-Hone®, 7/8" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials - Image 4](https://m.media-amazon.com/images/I/51FcAst9eLL.jpg)
![Brush Research BC78400AO Flex-Hone®, 7/8" (22.2mm) Diameter, 400 Grit, Aluminum Oxide, for Aluminum, Brass, Bronze and Softer Non-Ferrous Materials - Image 5](https://m.media-amazon.com/images/I/51cd3+2jIcL.jpg)

## Available Options

This product comes in different **Size, Style** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Mandatory tool for proper Nickasil cylinder prep when replacing pistons and rings
*by K***O on May 16, 2024*

I decided to rebuild my snowmobile motors as preventative maintenance, and was replacing pistons and rings. The piston suppliers all recommend cylinder prep with these type of ball hones. I bought two hones, one for my 500 cc sleds and one for my 800 cc sled. There are many grits and compounds available, but for Nickasil cylinders these 320 grit Aluminum Oxide versions are recommended. They worked perfectly for de-glazing and refreshing the crosshatch to help in proper cylinder oiling and piston and ring break-in. Choose the ball hone size you need based on the actual cylinder bore diameter. If you buy the hone that matches your diameter it is actually slightly oversized to create just the right amount of pressure to the cylinder wall for effective honing. Using these ball hones takes a bit of technique, but in a home shop environment I found doing the honing in a 5 gallon bucket worked to contain the lube oil from flinging all over the shop, I also made a short spacer to place under the bottom of the cylinder edge inside the bucket to lift the cylinder just enough off the bottom to allow the hone to effectively reach through the cylinder with a full stroke, but not protrude too far through and allow the balls to wrap the lip and bind. Holding the cylinder solid in the bucket also helped to keep the hone centered within the cylinder as cocking it at any angle while holding the cylinder by hand tended to end up with the hone hooking a port or the lip and stopping the process (my first attempts were a bit of a learning curve). Once I figured out how to hold the cylinder and limit the travel properly the remaining cylinders were easy to complete. If you do bind the hone and twist some of the ball fingers, they are very forgiving, and easy to re-set the fingers, straighten them out, and continue on, being more careful about your process. These hones should last forever if you're only using them periodically in a home shop. Using them per the included instructions left a beautiful surface with correctly angled cross-hatch, and made for a perfect top-end rebuild. These are far better than the old spring loaded stone-hones of old, especially for nickasil. These also have a far less likelihood of catching a port if you keep it centered. And if it does catch one due to your (My) own mistakes, it will simply bend around itself but not cause any damage, unlike the potential damage that could be caused if a stone catches a port with the old style hones. Highly recommend this product and the seller.

### ⭐⭐⭐⭐⭐ LS1 valve guide hone
*by C***N on October 15, 2025*

Worked great for LS1 head valve guides when I had to replace a broken one. Easy to use and the correct size. Priced right for what it does.

### ⭐⭐⭐⭐⭐ Very good quality!
*by N***N on July 27, 2025*

Great product!! Worked perfectly!! Will definitely buy again!

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-02-12*