# MasterPolish final polish

Buehler's alumina and colloidal-silica blend for final specimen polishing, with product distinctions and dated safety-document limits.

Reviewed: 2026-10-29

Tags: abrasives, metallography, specimen-preparation

## Identity and purpose

MasterPolish Final Polish blends high-purity alumina and colloidal silica. The ordering table lists part **40-10084**, **32 oz [0.95 L]**, **0.05 µm** and approximately **pH 9**. The product prose calls it “MasterMet Polish,” while the table and matching SDS identify MasterPolish. Buehler describes it as suitable for water-sensitive materials. The 2017 US SDS lists 10–40% water by weight for that revision. [Product page][product] [2017 US SDS][old-us]

Buehler’s TECHNotes describes alumina’s mechanical removal and silica’s chemical and mechanical action in removing residual deformation after diamond polishing. [TECHNotes, pp. 1–2][technotes] See [Finishing process references](../../processes/finishing/index.md) for production deburring and edge requirements.

## Size and formulation language

The product page gives both 0.050 µm and 0.05 µm. These are the same numerical size. The May 2014 quick-reference guide attaches 0.05 µm specifically to the alumina within the blend. Neither source supplies a separate silica particle-size distribution or blend ratio for MasterPolish. [Product page][product] [2014 guide][guide]

As a unit conversion, 0.05 µm equals 50 nm. This is an abrasive-size designation, not a claim that the specimen has 50 nm roughness. The sources provide no MasterPolish maximum particle size, measured roughness guarantee or universal polishing time.

"Minimal water" does not mean water-free. The historical US SDS lists water at 10–40% by weight. That broad disclosure applies to the 2017 document, not every later formulation or bottle. [US SDS, revision 2, section 3][old-us]

## Material applicability and limits

TECHNotes volume 8, issue 4, revision 1 lists MasterPolish for **most magnesium alloys**, cobalt alloys, **most iron alloys**, nickel and metal matrix composites. Its separate discussion says water-sensitive samples can use MasterPolish in many cases. Those qualifications do not establish compatibility with every alloy or composite phase. [TECHNotes, pp. 1, 3][technotes]

The May 2014 guide describes use on ferrous materials, nickel- and cobalt-base materials and metal composites. Its removal and finish claims are qualitative, without a numerical rate, roughness parameter or acceptance criterion. [2014 guide][guide]

Explanatory synthesis. The combination of abrasive removal and chemical action makes both the material and the intended observation relevant. A suitable appearance for one specimen does not establish preserved phase geometry, absence of selective attack or suitability for another analysis. No exact alloy-specific recipe, cloth, force, speed, dilution or cleaning method is established here.

## Neighboring products

Buehler lists these as distinct products. Similar names or abrasive sizes do not establish interchangeable formulations. [Product page][product]

| Product | Distinction in the current product page |
| --- | --- |
| MasterPolish | Alumina and colloidal-silica blend, 0.05 µm, approximately pH 9, with minimal water. |
| MasterPrep | Seeded-gel alumina suspension, nominal 0.05 µm, approximately pH 10.5 in the page's prose. |
| MasterMet | Colloidal silica, nominal 0.06 µm, approximately pH 10.5 in the prose. |
| MasterMet 2 | Non-crystallizing colloidal silica, nominal 0.02 µm. The same page gives approximately pH 11 in the prose and 10.5 in its product table. |
| MicroPolish | Alumina suspension. Code 40-10083 belongs to its 0.05 µm, 6 oz package, not MasterPolish. |

These pH descriptions are source-specific. The web ordering table and TECHNotes give approximately pH 8.5 for MasterPrep and 10 for MasterMet, differing from the same page's prose. The sources do not explain those differences. MasterPolish's approximately pH 9 description agrees between these sources. [TECHNotes, p. 1][technotes] [Product page][product]

**MasterPolish 2 is also a separate identity.** Buehler's 2014 guide describes its 0.06 µm proprietary formulation for ceramics, while the SDS index lists MasterPolish 2 Suspension separately from MasterPolish Suspension. Ceramic claims from that entry do not establish MasterPolish 40-10084 performance. [2014 guide][guide] [SDS index][index]

## Dated safety and composition evidence

The SDS index separates MasterPolish Suspension into entries before 31 July 2023 and after 1 August 2023. The linked newer US document itself has an issue date of **19 February 2024**, version **1.0**, SDS ID **1341971**, and product code **40-10084**. The index boundary is not the document's issue date. [SDS index][index] [2024 US SDS, section 1][new-us]

| Document | Evidence for that document and jurisdiction |
| --- | --- |
| US SDS 1341971_A, revision 2, 13 April 2017 | Section 2 classifies skin irritation category 2 and eye irritation category 2B. Section 3 discloses water 10–40%, silicon dioxide 1–40%, aluminum oxide 1–40%, hydroxyethyl cellulose 1–40% and propane-1,2-diol 5–20%, with exact concentrations withheld. Section 9 has no pH data. Section 15 says no Proposition 65 chemicals. [2017 US SDS][old-us] |
| European English SDS 1341971_E, revision 3, 13 April 2017 | Section 2 classifies skin and eye irritation category 2 under CLP, with H315 and H319. Section 9 provides no particle-size distribution. [2017 European SDS][old-eu] |
| US SDS 1341971, version 1.0, 19 February 2024 | Section 2 gives no GHS US classification. Section 3 reports no substances requiring disclosure under its stated HazCom criteria. Section 9 gives pH 8–11. Section 15 nevertheless lists aluminum oxide at 10–30% and a California warning concerning diethanolamine exposure. [2024 US SDS][new-us] |

The newer document's section 3 is not a complete ingredient inventory and does not establish absence of alumina or silica. The changed disclosures and classifications do not identify the cause of the change or establish an exact reformulation history. Approximate pH 9 in product literature and the SDS range 8–11 have different descriptive scopes. Neither is a lot-specific measurement or acceptance tolerance. [2024 US SDS, sections 3, 9, 15][new-us]

The 2024 SDS still specifies ventilation, protective gloves, safety glasses and protective clothing. Its storage guidance calls for cool conditions away from heat and sunlight. A lack of GHS classification is not evidence that exposure controls are unnecessary. Safety documentation describes handling and hazards; it does not validate polishing performance. [2024 US SDS, sections 7–8, 16][new-us]

## Source coverage

Reviewed **29 October 2026 PDT**. The product page and SDS index are undated retrieval snapshots. The complete five-page TECHNotes document is marked **updated May 2024**. The one-page quick-reference guide is marked **05/14**. Both historical SDS documents and the newer US SDS were read in full. [TECHNotes][technotes] [2014 guide][guide] [SDS index][index]

The reviewed sources do not establish a complete MasterPolish formulation, a lot-linked change history, current regional availability beyond the displayed package, shelf life, a quantitative water-sensitivity threshold or a universal finish. They also do not prove a particular shop's installed capability or approved preparation method.

[product]: https://www.buehler.com/products/grinding-and-polishing/grinding-and-polishing-consumables/final-polishing-suspensions/
[technotes]: https://www.buehler.com/assets/solutions/technotes/How_to_Select_and_Use_Final_Polishing_Oxide_Media.pdf
[guide]: https://www.buehler.com/assets/posters/0514_Quick-Ref-Guide-to-Final-Polishing-Solutions.pdf
[index]: https://www.buehler.com/solutions/buehler-literature/safety-data-sheets/
[old-us]: https://www.buehler.com/assets/SDS/US/1341971_A_MasterPolish_EN.PDF
[old-eu]: https://www.buehler.com/assets/SDS/UK/1341971_E_MasterPolish_EN.PDF
[new-us]: https://www.buehler.com/assets/SDS/US/MasterPolish-Suspension-US-English.pdf