Flex-Hone Types & Configurations
Flex-Hone® Types & Configurations: Standard, Tapered, Stepped & Special Designs
Not every bore is cylindrical. Flex-Hone® tools are available in numerous configurations – from the standard cylinder to fully custom-made designs.
At a Glance
- The Standard Flex-Hone® covers 80% of all applications: cylindrical bores from 4 to 965 mm
- Tapered configurations for valve seats, tapered bores and tool holders
- Stepped configurations for bores with different diameters (e.g., stepped bores in gearbox housings)
- All configurations available in all abrasives and grits
- Custom designs available from precision pro – even single units
Standard Flex-Hone®: The All-Rounder
The Standard Flex-Hone® is the most widely used model, designed for all cylindrical through and blind bores. It consists of flexible nylon filaments carrying spherical abrasive globes – the world-renowned "Globe Design."
- Diameter range: 4 mm to 965 mm (0.156" to 38")
- Abrasive: SC (Silicon Carbide), AO (Aluminum Oxide), BC (Boron Carbide), Diamond
- Grit: 20 (extremely coarse) to 800 (extremely fine)
- Shank: Cylindrical, fits any standard drill chuck
- Applications: Engine cylinders, hydraulic cylinders, bushings, bearing seats, valve guides, cross-drilled holes – virtually any cylindrical bore
Why "flexible"? The name Flex-Hone® comes from its self-aligning design: The globe-tipped filaments automatically conform to the bore diameter. This eliminates the adjustment required with conventional honing tools. Additionally, the tool corrects slight out-of-roundness and follows the existing bore geometry rather than altering it.
Tapered Flex-Hone®
Tapered bores are more common than often assumed: valve seats, tool tapers (Morse tapers), tapered bearing seats and combustion chambers. A Standard Flex-Hone® can only provide limited help here, as it is designed for cylindrical bores.
- Design: The abrasive globes are arranged in a tapered pattern – they follow the taper angle of the bore
- Taper angle: Available in standard taper angles (e.g., Morse taper) and custom angles
- Applications: Valve seats in cylinder heads, Morse tapers in spindles, tapered sealing surfaces, tapered bearing seats
- Advantage: Uniform contact pressure across the entire tapered surface – no "lifting off" at the larger-diameter end
Important: Tapered Flex-Hone® tools must match the exact taper angle of the bore. An incorrect angle leads to uneven material removal. When ordering, specify the taper angle and the diameter range (small/large).
Stepped Flex-Hone®
Stepped bores – bores with two or more different diameters – are found in gearbox housings, hydraulic valve blocks and compressor housings. Normally, you would need a separate tool for each step and would have to re-chuck multiple times.
- Design: One tool with two or three diameter steps on a common shank
- Advantage: Both (or all three) steps are machined in a single pass – no tool change required
- Precision: The steps are precisely matched to the bore diameters
- Applications: Gearbox housings, valve blocks, compressor bores, stepped bearing seats
Stepped Flex-Hone® tools are typically custom-made – manufactured to specification. When requesting a quote, provide the diameter of each step, the step lengths and the total stroke.
Special Configurations
In addition to standard, tapered and stepped, there are further special designs for particular applications:
- Extended Length For deep bores where the standard tool cannot reach the machining area. Extended shank available in various lengths – up to over 1 meter. Typical for deep hydraulic cylinders, tubes and extruder barrels.
- Ultra-Flex For bores that must be accessed through angles or curves (e.g., cross-drilled holes). The shank is particularly flexible and can tolerate slight deflections.
- Micro-Flex-Hone® (Miniature Brushes) For bores under 10 mm – down to 0.5 mm. Designed specifically for precision engineering, medical technology and watchmaking applications. Detailed guide: Miniature Brushes in Detail.
- Dual-Head Two abrasive sections on a single shank, separated by an uncoated segment. For bores where two separate areas must be machined without touching the area in between.
- Custom Design Any combination of diameter, length, abrasive, grit, shank type and stepping is available as a custom design. Even single units are manufactured.
All Configurations Compared
| Type | Bore Type | Diameter | Availability | Typical Application |
|---|---|---|---|---|
| Standard | Cylindrical | 4–965 mm | In stock | Engine, hydraulic, bearing seats |
| Tapered | Tapered | Custom | Stock / Custom | Valve seats, Morse tapers |
| Stepped | Stepped | Custom | Custom | Gearbox housings, valve blocks |
| Extended Length | Cylindrical (deep) | Standard | Stock / Custom | Deep cylinders, tubes |
| Ultra-Flex | Angular access | Standard | Custom | Cross-drilled holes, angled channels |
| Micro-Flex | Cylindrical (micro) | 0.5–10 mm | In stock | Precision engineering, medical |
| Dual-Head | 2 zones | Custom | Custom | Dual bearing seats |
How to Find the Right Configuration
Use this checklist to find the right Flex-Hone® model in three steps:
- Determine bore geometry Cylindrical, tapered or stepped? Cylindrical → Standard. Tapered → Tapered. Stepped → Stepped. When in doubt: have the bore drawing or technical drawing ready.
- Measure diameter and depth Diameter → determines tool size (nominal bore diameter). Depth → determines whether a standard shank is sufficient or an extension is needed. Standard shank length: approx. 4× tool diameter.
- Define material and objective What material is being machined → determines abrasive. What result is needed → determines grit. What surface roughness is required → determines fine vs. coarse grit.
Practical tip: If you are unsure, contact us with the following information: bore diameter, bore depth, material, desired result. With these details, we can immediately recommend the right tool in 90% of cases – or provide a quote for a custom design in special situations.
| Range | Configurations | Recommendation | |
|---|---|---|---|
| Flex-Hone® Standard | 4–965 mm, all grits | 80% of all applications Volume pricing | View range |
| Special & Accessories | Tapered, extended, honing oil | Special configurations & accessories Volume pricing | Select |
| Micro-Flex-Hone® | 0.5–10 mm diameter | Precision engineering & medical technology | Select |
Conclusion: The Right Tool for Every Bore
The Flex-Hone® system is far more than a standard tool: With tapered, stepped, extended and custom configurations, there is a solution for virtually any bore geometry. The key lies in the correct specification: diameter, bore type, material and desired result. Once you have these four pieces of information, we'll find the right tool – or manufacture it.
FAQ
Can I use a Standard Flex-Hone® for a slightly tapered bore?
With very slight taper (< 1°), this is possible – the flexible globe carriers adapt slightly. From approx. 2° taper angle, however, the contact pressure becomes uneven: too much at the smaller diameter, too little at the larger. In this case, order a tapered configuration.
How long does a custom design take?
Custom designs are manufactured in the USA. Lead time is typically 4–6 weeks from order confirmation. For urgent projects: contact us – in some cases, standard tools can be adapted or alternatives from stock can be suggested.
Are there minimum order quantities for custom tools?
No – even single units are manufactured as custom designs. Naturally, unit costs are lower at higher quantities. Typical custom order quantities range between 1 and 50 pieces.
Which Flex-Hone® do I need for a hydraulic cylinder with 500 mm depth?
A Standard Flex-Hone® with extended shank. Determine the diameter, select the matching standard tool, and specify the required overall length. Detailed information on hydraulic cylinder finishing: Hydraulic Cylinder Finish.
Discover Flex-Hone® Tools
Standard configurations in stock, custom designs on request.
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