# Felt polishing wheels

Plain felt compound carriers, impregnated variants, supplier-specific hardness, mounting dimensions, and speed terminology.

Reviewed: 2026-10-29

Tags: abrasives, polishing, felt, reference

## Identity and boundaries

PFERD’s **44367110** is a medium 100 × 20 mm felt wheel with a **10 mm hole**. Its optimum speed is **900–1,800 rpm** and its maximum is **6,100 rpm**. PFERD’s soft shank-mounted **44383020** instead lists **6,300 rpm optimum** and **20,000 rpm maximum**. [PFERD Catalogue 4, pp. 179–180][pferd] Plain felt carries separately applied compound. Spartan also offers felt with abrasive fixed into it. [Spartan Felt selection guide, pp. 1–2][spartan]

Several different constructions share polishing terminology.

| Construction | Distinguishing feature |
| --- | --- |
| Plain felt carrier | Compound supplies the selected abrasive. The wheel's fiber and hardness remain separate properties. [Spartan, pp. 1–2][spartan] |
| Abrasive-impregnated felt | Spartan fixes abrasive within felt using water-based chemistry. This can reduce or eliminate separately applied compound for its tools. [Spartan, p. 2][spartan] |
| Felt with metal insert | PFERD's FK SC MS has a brass inlay and remains intended for use with polishing paste. A metal insert is not an abrasive grit designation. [PFERD MS product page][pferd-ms] |
| Nonwoven abrasive wheel | 3M Scotch-Brite wheels contain abrasive grain within a nylon web. Convolute construction wraps that material around a core. Unitized construction presses layers together. [3M wheel construction][3m] |
| Stitched cloth buff | Gesswein's muslin buff 1402660 has cloth plies, concentric stitching, and a leather center containing shellac. Its construction differs from a solid felt wheel. [Gesswein stitched muslin buff][muslin] |
| Bonded grinding wheel | A bonding medium holds abrasive grains and gives the wheel strength. Norton distinguishes the grain, bond, and porosity. [Norton bond selection][norton] |

## Fiber, hardness, and dimensions

Gesswein identifies its hard felt wheel SKU 2800020 as wool, with no synthetic fibers or fillers. The listed wheel is square-edged, 1/2 in diameter and 1/8 in thick, with a 1/16 in arbor hole. The description calls the center a pinhole and excludes the mandrel. These specifications describe this supplier's product, not all felt wheels. [Gesswein hard felt wheel][gesswein]

Spartan distinguishes wool media from synthetic media, typically polyester or nylon. It also explains that density is mass per volume, whereas hardness describes a different property. Compression can increase both. [Spartan, pp. 1–2][spartan]

Synthesis from these sources and the PFERD tables below. "Soft," "medium," and "hard" are supplier-defined labels in this reference. The reviewed sources provide no cross-supplier equivalence. A hardness name does not supply a fiber percentage, a numerical density, or an abrasive-particle size. Density has units such as kg/m³ or g/cm³. Neither a wheel's diameter nor its thickness describes abrasive-particle size. A compound's abrasive concentration requires a separate basis, such as abrasive mass per mass of complete compound.

The following examples preserve PFERD's distinct dimension and speed columns. They are a small comparison, not an operating schedule. [PFERD Catalogue 4, pp. 179–180][pferd]

| Exact product | Wheel dimensions | Mounting dimension | Supplier version | Optimum RPM | Maximum RPM |
| --- | --- | --- | --- | --- | --- |
| FK SC 10020/10 M, item 44367110 | 100 mm diameter × 20 mm thick | 10 mm hole | M, medium | 900–1,800 | 6,100 |
| FLS 3020/6 W, item 44383020 | 30 mm diameter × 20 mm thick | 6 mm shank, 40 mm shank length | W, soft | 6,300 | 20,000 |

The FK SC wheel takes arbor BO 8/10. The arbor table gives BO 8/10 6-20, item 42400008, an 8 mm shank, 10 mm hole suitability, and 6–20 mm clamping range. [PFERD, pp. 180 and 184][pferd]

Synthesis. Matching one nominal diameter does not establish a complete mounting arrangement. Wheel thickness, center construction, arbor identity, clamping range, and the drive connection describe different parts of the assembly. The examples do not establish an interchangeable inch-size fit or an assembly speed rating.

## Rotational speed and surface speed

PFERD lists optimum RPM separately from maximum RPM and prohibits exceeding the indicated maximum. Its FK SC wheels act mainly at their periphery. [PFERD, pp. 175 and 180][pferd] A maximum is a limit, not a recommended polishing setting.

Surface speed expresses distance traveled at the contact diameter per unit time. Spartan gives the circumference-based relationship. [Spartan, p. 3][spartan] In consistent metric units, the same relationship is:

```text
v = π × D × n / 60
v = surface speed in m/s
D = actual contact diameter in m
n = rotational speed in revolutions/min
```

Calculated illustration, not a process recommendation. At an assumed 100 mm contact diameter and 1,000 RPM, the circumference travels approximately 5.24 m/s. At an assumed 30 mm contact diameter and the same RPM, it travels approximately 1.57 m/s. The diameter assumption is essential. This arithmetic neither establishes a suitable polishing speed nor replaces a wheel, arbor, assembly, or machine limit.

## Compound, application, and contamination limits

PFERD describes FK SC MS wheels for pre-polishing with diamond grinding pastes. Its product page calls for an unused polishing tool when the paste changes. This is evidence for separating pastes on that product, not a cleanliness certification. [PFERD MS product page][pferd-ms]

Dremel separately identifies its 429 felt wheel as 25.4 mm diameter and specifies mandrel 401. Dremel lists metals, plastics, stones, ceramics, and glass as applications, and permits use with or without compound. That product-specific wording limits the opening carrier definition. It does not establish that every felt wheel requires compound or suits those workpieces. [Dremel 429 product page][dremel]

Synthesis. Application evidence belongs to the exact wheel and compound combination. Plain felt, brass-containing felt, and abrasive-impregnated felt cannot share an assumed composition or contamination limit. A compound safety data sheet describes that compound, not the bare wheel or the combined polishing debris. The sources reviewed here do not establish residue-free performance, coating compatibility, a universal removal rate, or a guaranteed roughness. No compound loading quantity, pressure, dwell time, or production recipe is derived.

## Source versions and coverage limits

Reviewed 29 October 2026 PDT. The page remains an unpublished research draft.

- [Spartan Felt, Polishing: Felt selection and use guidelines][spartan]. Four pages, revision identified by the filename as 12-11-23. Definitions, fiber discussion, hardness, impregnation, speed tables, application table and footnotes were read. Its process suggestions are not universal settings. The bob-speed table has entries inconsistent with its formula, so those cells are not adopted.
- [PFERD, Catalogue 4, Fine grinding and polishing tools][pferd]. `wzh25` English international PDF, with PDF metadata dated 3 December 2024. Tables on pp. 179–180 and 184 support the examples, without numerical fiber blend or density. The separate [MS product page][pferd-ms] is an undated web snapshot.
- [Gesswein hard felt wheel][gesswein], [Gesswein stitched muslin buff][muslin], [Dremel 429][dremel], and [3M Scotch-Brite wheels][3m]. Undated product-page snapshots reviewed on the date above. Their specifications and construction descriptions apply to the identified products.
- [Norton, Bond selection for production grinding][norton]. Article dated 20 July 2017. Used only to distinguish bonded-wheel construction.

No wheel-specific SDS, compound-specific SDS, lot certificate, mounting manual, or applicable compliance certificate was evaluated. Public grinding-wheel terminology alone does not establish that a bonded-abrasive standard applies to a plain felt carrier. Workpiece acceptance, cleanliness, dimensional change, and the complete assembly's permitted operation remain outside this generic reference.

Related reference. [Finishing process references](../../processes/finishing/index.md).

[spartan]: https://spartanfelt.com/wp-content/uploads/2023/12/WOOL-FELT-Selection-and-Use-Guide-Rev-12-11-23.pdf
[pferd]: https://assets.pferd.com/pfd/products/pdfs/wzh25-catalogue-4-web-int-en.pdf
[pferd-ms]: https://int.pferd.com/en/felt-wheels?a%5Bdiam-outer-tds%5D=100+mm&a%5Bshape-tds%5D=Disc&a%5Btype-tds%5D=MS+%28metal+insert%29&a%5Bwidth-tds%5D=20+mm
[gesswein]: https://www.gesswein.com/products/hard-felt-wheels
[muslin]: https://www.gesswein.com/products/white-muslin-buff-6-x-60-ply-stitched
[3m]: https://www.3m.com/3M/en_US/metalworking-us/products/scotch-brite-wheels/
[norton]: https://www.nortonabrasives.com/en-us/resources/expertise/bond-selection-production-grinding
[dremel]: https://www.dremel.com/us/en/p/429-2615000429